Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Hematology 1 (Laboratory) > Manual, Semiautomated, and Point-of-Care Testing in Hematology (from Rodak [5th ed.]) > Flashcards

Manual, Semiautomated, and Point-of-Care Testing in Hematology (from Rodak [5th ed.]) Flashcards

1
Q

When to use manual methods (in terms of cting cells from whole bld)?

A

1) When an instrument is nonfxnal and there is no backup (in remote labs in Third World countries)
2) / in a disaster situation (when testing is done in the field)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Are manual cts also performed in body cell fluids?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the instruments (/ equipment) used for performing manual cell cts?

A

1) Hemacytometer (/ counting chamber)
2) Calibrated, automated pipettes (for performing manual dilutions)

Others:
1) Diluents (w/c are commercially preped / lab preped)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Is the principle for the performance of cell cts essentially same for WBCs, RBCs, and PLTs?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

If the principle for the cell cts for WBCs, RBCs, and PLTs are all the same, is there some other factors (when it comes to cell cting [of such cells]) present? If there is, enumerate.

A

Yes, only the ff vary:

1) Dilution
2) Diluting fluid
3) Area cted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Can sperm be manually cted?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In manual cell ct, what is the most common counting chamber used?

A

Levy chamber (w/ improved Neubauer ruling)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the characteristics of the Levy chamber?

A

1) It is composed of 2 raised surfaces
2) Each of the raised surface has a 3 mm X 3 mm square cting area / grid
3) The 2 raised surfaces is separated by an H-shaped moat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the total area of the cting area / grid in 1 raised surface of the Levy chamber?

A

9 mm^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the measurement of each small square (from the 1 big square])?

A

1 mm X 1 mm squares

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

In the 1 big square, where are the sites (/ also called as WBC squares) where WBCs are cted?

A

In the 4 corner small squares (whereas each small square is subdivided into 16 tiny squares)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the measurement of each of the tiny squares (present inside each small square)?

A

0.2 mm X 0.2 mm (w/c is 1/25 of the center square or 0.04 mm^2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the impt component (/ part) of the counting chamber that should be placed on top of the cting surfaces?

A

Coverslip

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the distance between each cting surface and the coverslip?

A

0.1 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Since the distance between each cting surface and the coverslip (in the cting chamber) is 0.1 mm, what is the total volume of 1 entire grid / cting area (/ 1 big square) on 1 side of the hemacytometer?

A

0.9 mm^3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What must be the characteristic of hemacytometers and coverslips?

A

They must meet the specifications of the NBS (whereas this initials is seen on the chamber)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the meaning of NBS?

A

National Bureau of Standards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

True or False

When the dimensions of the hemacytometer are thoroughly understood, the area cted can be changed to facilitate the cting of sxs w/ extremely low / high cts

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the general formula for manual cell cts (w/c can be used to calculate any type of cell ct)?

A

Total count = cells counted X dilution factor
——————————————-
area (mm^2) X depth (0.1)

OR

                  cells counted X dilution factor X 10  Total count = ---------------------------------------------------
                                    area (mm^2)

Note:

1) 10 on the 2nd formula is the reciprocal of depth
2) Calculation yields the # of cells/mm^3 (whereas 1 mm^3 is equal to 1 uL
3) The ct/uL is converted to ct/L (by multiplying by a factor of 10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where are the sites where RBCs are cted (in the hemacytometer)?

A

In the central small square (from the big square) -> in the 4 corners and 1 central tiny square

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where is the site where PLTs are cted (in the hemacytomer)?

A

In the entire central small square (from the big square)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the bld cells that can be cted via the use of hemacytomer?

A

1) RBCs
2) WBCs
3) PLTs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the WBC / leukocyte ct (obtained via the use of hemacytometer)?

A

It is the # of WBCs in 1 L of 1 uL of bld

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the anticoagulant of the WB sx (if sx is obtained via venipuncture)?

A

Ethylenediaminetetraacetic acid (EDTA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the diluent of bld (if the sx is obtained via skin puncture)?

A

1) 1% buffered ammonium oxalate
2) / weak acid solution
a. 3% acetic acid
b. / 1% HCl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the action of diluting fluid (for WBC ct [via the use of hemacytometer)?

A

It lyses the nonnucleated RBCs in the sx (to prevent their interference in the ct)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the typical dilution of bld for WBC ct (using hemacytometer)?

A

1:20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the simplified procedure for WBC ct (via the use of hemacytometer)?

A

1) The hemacytometer is charged (filled) w/ the well-mixed dilution
2) The hemacytometer is placed under a microscope
3) The # of cells present in the 4 large corner squares (/ 4 small squares | having a measurement of 4 mm^2) are cted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the complete procedure of WBC ct (via the use of hemacytometer)?

A

1) Clean the hemacytometer and coverslip w/ alcohol and dry thoroughly w/ a lint-free tissue. Place the coverslip on the hemacytometer
2) Make a 1:20 dilution by placing 25 uL of well-mixed bld into 475 uL of WBC diluting fluid in a small test tube
3) Cover the tube and mix by inversion
4) Allow the dilution to sit for 10 mins to ensure that the RBCs have lysed. The solution will be clear once lysis has occurred. WBC cts should be performed within 3 hrs of dilution
5) Mix again by inversion and fill a plain microhct tube
6) Charge both sides of the hemacytometer by holding the microhct tube at a 45-degree angle and touching the tip to the coverslip edge where it meets the chamber floor
7) After charging the hemacytometer, place it in a moist chamber for 10 mins before cting the cells to give them time to settle. Care should be taken not to disturb the coverslip
8) While keeping the hemacytometer in a horizontal position, place it on the microscope stage
9) Lower the condenser on the microscope and focus by using the low-power (10x) objective lens (100x total magnification). The cells should be distributed evenly in all of the squares
10) For a 1:20 dilution, ct all of the cells in the 4 corner squares, starting w/ the square in the upper left-hand corner. Cells that touch the top and left lines should be cted; cells that touch the bottom and right lines should be ignored
11) Repeat the ct on the other side of the cting chamber. The difference between the total cells cted on each side should be < 10%. A greater variation could indicate an uneven distribution, w/c requires that the procedure be repeated
12) Ave the # of WBCs cted on the 2 sides. Using the ave, calculate the WBC ct using 1 of the equations given earlier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How to make a 1:20 dilution for WBC ct?

A

25 uL well-mixed bld + 475 uL diluting fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What should be the angle when charging the hemacytometer?

A

45 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What objective should be used for WBC ct?

A

LPO (10x)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the cells included in WBC ct?

A

Cells that touch the top and left lines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the cells that are not included in the WBC ct?

A

Cells that touch the bottom and right lines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Provide an ex of the application of calculation (using the 1st formula) for WBC ct (via the use of hemacytometer)

A

A 1:20 dilution is used
1) The ct on 4 large squares (/ 4 small squares) are 23, 26, 22, and 21, total ct of 92; while the ct on the other 4 large squares (/ 4 small squares) on the other side of the chamber are 28, 24, 22, and 26, total ct of 100. The difference between sides is < 10%
2) Average the 2 total cts (from the 2 sides) -> 92 + 100 = 192/2 = 96
3) Execute the formula
cells counted X dilution factor
WBC count = ——————————————–
area counted (mm^2) X depth

                = 96 X 20 
                  --------------
                    4 X 0.1

               = 4800/mm^3 or 4800 uL or 4.8 X 10^3/uL or 4.8 X 10^9/L

Alternatively, a 1:100 dilution may be used cting the # of the cells in the entire cting area (9 large squares, 9mm^2 [/ 9 small squares]) on both sides of the chamber.

Ex. 54 cells (ave) were cted in the entire cting area on both sides of the chamber

Execute the formula:
cells counted X dilution factor
WBC count = ——————————————–
area counted (mm^2) X depth

                = 54 X 100
                   --------------
                    9 X 0.1

                = 6000/mm^3 or 6000/uL or 6.0 X 10^3/uL or 6.0 X 10^9/L
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

True or False

The reference intervals (of WBC ct) [via the use of hemacytometer]) may vary slightly accdg to the population tested and should be established for each lab

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the sources of error and comments for WBC ct (via the use of hemacytometer)?

A

1) The hemacytometer and coverslip should be cleaned properly before they are used. Dust and fingerprints may cause difficulty in distinguishing the cells
2) The diluting fluid should be free of contaminants
3) If the ct is low, a greater area may be cted (e.g., 9 mm^2) to improve accuracy
4) The chamber must be charged properly to ensure an accurate ct. Uneven flow of the diluted bld into the chamber results in an irregular distribution of cells. If the chamber is overfilled / underfilled, the chamber must be cleaned and recharged
5) After the chamber is filled, allow the cells to settle for 10 mins before cting
6) Any nucleated RBCs (NRBCs) present in the sx are not lysed by the diluting fluid. The NRBCs are cted as WBCs because they are indistinguishable when seen on the hemacytometer. If 5 or more NRBCs/100 WBCs are observed on the diff ct on a stained peripheral blood film, the WBC ct must be corrected for these cells. This is accomplished by using the ff formula:

Number of NRBCs per 100 WBCs + 100

  • > report the result as the “corrected” WBC ct
    7) The accuracy of the manual WBC ct can be assessed by performing a WBC estimate on a Wright-stained peripheral bld film made from the same sx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How to make a moist chamber?

A

A moist chamber may be made by placing a pc of damp filter in the bottom of a petri dish. An applicator stick (broken in half) can serve as a support for the hemacytometer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is PLT ct (via the use of hemacytometer)?

A

It is the # of PLTs in 1 L or 1 uL of WB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are the characteristics of PLTs?

A

1) They adhere to foreign objects and to each other (w/c makes them difficult to ct)
2) They are small (having a diameter of 2 - 4 um)
3) They can be confused easily w/ dirt / debris (but their shape and color help distinguish them from highly refractile dirt and debris)
4) They appear round / oval
5) They display a light purple sheen (when phase-contrast microscopy is used)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is the anticoagulant used for PLT ct (via the use of hemacytometer | if the sx is obtained via venipuncture)?

A

EDTA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is done to WB in PLT ct?

A

It is diluted 1:100 w/ 1% ammonium oxalate (to lyse the nonnucleated RBCs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Where are PLTs cted (via the use of hemacytometer)?

A

In the 25 small squares (/ 25 tiny squares) in the large center square (1 mm^2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What type of microscope is used for PLT ct (via the use of hemacytometer | in the reference method described by Brecher and Cronkite)?

A

Phase-contrast microscope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

True or False

Only phase-contrast microscope can be used for PLT ct (via the use of hemacytometer)

A

False, because a light microscope can also be used, but visualizing PLTs may be more difficult

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the complete procedure of PLT ct (via the use of hemacytometer)?

A

1) Make a 1:100 dilution by placing 20 uL of well-mixed bld into 1980 uL of 1% ammonium oxalate in a small test tube
2) Mix the dilution thoroughly and charge the chamber
-> note: a special thin, flat-bottomed cting chamber is used for phase-microscopy PLT cts)
3) Place the charged hemacytometer in a moist chamber for 15 mins to allow the PLTs to settle
4) PLTs are cted using the 40x objective lens (400x total magnification). The PLTs have a diameter of 2 - 4 um and appear round or oval, displaying a light purple sheen when phase-contrast microscopy is used. The shape and color help distinguish PLTs from highly refractile dirt and debris. “Ghost” RBCs often are seen in the bg
5) Ct the # of PLTs in the 25 small squares (/ 25 tiny squares) in the center square of the grid. The area of this center square is 1 mm^2. PLTs should be cted on each side of the hemacytometer, and the difference between the totals should be < 10%
6) Calculate the PLT ct by using 1 of the equations given earlier. Using the 1st equation as an ex, if 200 PLTs were cted in the entire center square (/ entire center small square)
-> 200 X 100
—————-
1 X 0.1
= 200,000/mm^3 or 200,000/uL or 200 X 10^3/uL or 200 X 10^9/L
7) The accuracy of the manual PLT ct should be verified by performing a PLT estimate on a Wright-stained peripheral bld film made from the same sx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

How to make a 1:100 dilution for PLT ct?

A

20 uL of well-mixed bld + 1980 uL of 1% ammonium oxalate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is used for phase-microscopy PLT cts?

A

A special thin, flat-bottomed cting chamber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are the sources of error and comments for PLT ct (via the use of hemacytometer)?

A

1) Inadequate mixing and poor collection of the sx can cause the PLTs to clump on the hemacytometer. If the problem persists after redilution, a new sx is needed. A skin puncture sx is less desirable because of the tendency of the PLTs to aggregate / form clumps
2) Dirt in the pipette, hemacytometer, or diluting fluid may cause the cts to be inaccurate
3) If fewer than 50 PLTs are cted on each side, the procedure should be repeated by diluting the bld to 1:20. If more than 500 PLTs are cted on each side, a 1:200 dilution should be made. The appropriate dilution factor should be used in calculating the results
4) If the pt has a normal PLT ct, the 5 small, RBC squares may be cted. Then, the area is 0.2 mm^2 on each side
5) The phenomenon of “platelet satellitosis” may occur when EDTA anticoagulant is used. This refers to the adherence of PLTs around neutrophils, producing a ring / satellite effect. Using Na citrate as the anticoagulant should correct this problem. Because of the dilution in the citrate etubes, it’s necessary to multiply the obtained PLT ct by 1.1 for accuracy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

True or False

Manual RBC cts are always performed

A

False, because manual RBC cts are rarely performed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Why are manual RBC cts rarely performed (specifically via the use of hemacytometer)?

A

Because of the inaccuracy of the ct and questionable necessity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Since manual RBC cts (via the use of hemacytometer) are rarely performed, what are the other more accurate manual RBC procedures that are desirable to be performed when automation is not available?

A

1) Microhct

2) Hgb conc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Answer the ff questions w/ regards to the given cells cted manually (/ bld cell cted manually | via the use of hemacytometer):

1) What is/are the diluting fluid/s?
2) What is/are the dilution/s?
3) What is the objective used?
4) What is/are the area/s cted?

Given cell cted: WBCs

A

1) 1% ammonium oxalate; / 3% acetic acid; / 1% HCl
2) 1:20; / 1:100
3) 10x
4) 4 mm^2; / 9 mm^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Answer the ff questions w/ regards to the given cells cted manually (/ bld cell cted manually | via the use of hemacytometer):

1) What is/are the diluting fluid/s?
2) What is/are the dilution/s?
3) What is the objective used?
4) What is/are the area/s cted?

Given cell cted: RBCs

A

1) Isotonic saline
2) 1:100
3) 40x
4) 0.2 mm^2 (5 small squares of center square [/ 5 tiny squares of center square])

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Answer the ff questions w/ regards to the given cells cted manually (/ bld cell cted manually | via the use of hemacytometer):

1) What is/are the diluting fluid/s?
2) What is/are the dilution/s?
3) What is the objective used?
4) What is/are the area/s cted?

Given cell cted: PLTs

A

1) 1% ammonium oxalate
2) 1:100
3) 40x; / phase
4) 1 mm^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

True or False

Capillary pipette and diluent reservoir systems are commercially available for WBC and PLT cts

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Provide 1 diluent reservoir system (/ bld diluting system | for manual WBC and PLT cts)

A

LeukoCheck™ (Biomedical Polymers, Inc., Gardner, MA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What are the components of LeukoCheck™?

A

1) A capillary pipette (calibrated to accept 20 uL of bld | this fits into a plastic reservoir)
2) A plastic reservoir (w/c contains 1.98 mL of 1% buffered ammonium oxalate that makes a 1:100 dilution of WB)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

How is LeukoCheck™ used?

A

1) Bld from a well-mixed EDTA-anticoagulated sx / from a skin puncture is allowed to enter the pipette by capillary action to the fill volume
2) The bld is added to the reservoir making a 1:100 dilution
3) After mixing the reservoir and allowing 10 mins for lysis of the RBCs, the reverse end of the capillary pipette is placed in the reservoir cap making a dropper
4) The 1st 3 / 4 drops of the diluted sx is discarded, and the capillary pipette is used to charge the hemacytometer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

True or False

Both WBC and PLT cts can be done from the same diluted sx (when using bld diluting system)

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

If bld diluting system (/ disposable bld cell ct dilution system) is used, where are WBCs cted?

A

They are cted in all 9 large squares (/ 9 small squares | 9 mm^2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What objective is used when doing WBC ct (via the use of bld diluting system)?

A

LPO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Where are PLTs cted if blood diluting system is used?

A

In 25 small squares (/ 25 tiny squares) in the center square (/ center small square | 1 mm^2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What objective is used for PLT ct if bld diluting system is used?

A

HPO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

True or False

The std formula is used to calculate the cell cts (if bld diluting system is used)

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Where is hgb located?

A

It is located within the RBC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What are the fxns of hgb?

A

1) To carry oxygen to the tissues

2) To carry CO2 from the tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the reference method for hgb determination (w/c is approved by the CLSI)?

A

Cyanmethemoglobin (hemoglobincyanide)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is the meaning of CLSI?

A

Clinical and Laboratory Standards Institute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is the procedure (/ principle) of cyanmethgb method?

A

1) Bld is diluted in an alkaline Drabkin solution of potassium ferricyanide, potassium cyanide, sodium bicarbonate, and a surfactant
2) The hgb is oxidized to methgb (Fe^3+) by the K ferricyanide K3Fe(CN)6
3) The K cyanide (KCN) then converts the methgb to cyanmethgb:
Hemoglobin (Fe^2+) + K3Fe(CN)6 -> methemoglobin (Fe^3+) + KCN -> cyanmethemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

True or False

The A of the cyanmethgb at 540 nm is indirectly proportional to the hgb conc (in the cyanmethgb method)

A

False, because the A of the cyanmethgb at 540 nm is directly proportional to the hgb conc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

In cyanmethgb method, is sulfhgb converted to cyanmethgb?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

In cyanmethgb method, is sulfhgb measured?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

True or False

In cyanmethgb method, sulfhgb fractions of > 0.05 g/dL are seldom encountered in clinical practice

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What is the complete procedure of cyanmethgb method (for hgb determination)?

A

1) Create a std curve, using commercially available cyanmethgb std
a. When a std containing 80 mg/dL of hgb is used, the ff dilutions should be made:
Hemoglobin Concentration | Blank | 5 | 10 | 15 | 20
-> Cyanmethgb std (mL) | 0 | 1.5 | 3 | 4.5 | 6
Cyanmethgb rngt (mL) | 6 | 4.5 | 3 | 1.5 | 0
b. Transfer the dilutions to cuvettes. Set the wavelength on the spectrophotometer to 540 nm and use the blank to set to 100% transmittance
c. Using semilogarithmic paper, plot percent transmittance on the y-axis and the hgb conc on the x-axis. The hgb concs of the control and pt sxs can be read from this std curve
d. A std curve should be set up w/ each new lot of rgnts. It also should be checked when alterations are made to the spectrophotometer (e.g., bulb change)
2) Controls should be run w/ each batch of sxs. Commercial controls are available
3) Using the pt’s WB anticoagulated w/ EDTA or heparin or bld from a capillary puncture, make a 1:251 dilution by adding 0.02 mL (20 uL) of bld to 5 mL of cyanmethgb rgnt. The pipette should be rinsed thoroughly w/ the rgnt to ensure that no bld remains. Follow the same procedure for the control sxs
4) Cover and mix well by inversion or use a vortex mixer. Let stand for 10 mins at room temp to allow full conversion of hgb to cyanmethgb
5) Transfer all of the solutions to cuvettes. Set the spectrophotometer to 100% transmittance at the wavelength of 540 nm, using cyanmethgb rgnt as blank
6) Using a matched cuvette, continue reading the % transmittance of the pt sxs and record the values
7) Determine the hgb conc of the control sxs and the pt sxs from the std curve.

76
Q

What are the sources of error and comments for cyanmethgb method (of hgb determination)?

A

1) Cyanmethgb rgnt is sensitive to light. It should be stored in a brown bottle or in a dark place
2) A high WBC ct ( > 20 X 10^9/L) or a high PLT ct ( > 700 X 10^9/L) can cause turbidity and a falsely high result. In this case, the rgnt-sx solution can be centrifuged and the supernatant measured
3) Lipemia also can cause turbidity and a falsely high result. It can be corrected by adding 0.01 mL of the pt’s plasma to 5 mL of the cyanmethgb rgnt and using this solution as the rgnt blank
4) Cells containing Hb S and Hb C may be resistant to hemolysis, causing turbidity; this can be corrected by making a 1:2 dilution w/ distilled H2O (1 part diluted sx + 1 part H2O) and multiplying the results from the std curve by 2
5) Abnormal globulins, such as those found in pts w/ plasma cell myeloma or Waldenström macroglobulinemia, may ppt in the rgnt. If this occurs, add 0.1 g of K carbonate to the cyanmethgb rgnt. Commercially available cyanmethgb rgnt has been modified to contain KH2PO4 salt, so this problem is not likely to occur
6) Carboxyhgb takes 1 hr to convert cyanmethgb and theoretically could cause erroneous results in sxs from heavy smokers. The degree of error is probably not clinically significant, however
7) Because the hgb rgnt contains cyanide, it is highly toxic and must be used cautiously. Consult the safety data sheet supplied by the manufacturer. Acidification of cyanide in the rgnt releases highly toxic hydrogen cyanide gas. A licensed waste disposal service should be contracted to discard the rgnt; rgnt-sx solutions should not be discarded into sinks
8) Commercial A stds kits are available to calibrate spectrophotometers
9) Handheld systems are commercially available to measure the hgb conc. An ex is the HemoCue (HemoCue, Inc., Brea, CA) in w/c hgb is converted to azidemethemoglobin and is read photometrically at 2 wavelengths (570 nm and 880 nm)

77
Q

What is the effect of the cyanmethgb method (for hgb determination)?

A

It avoids the necessity of sx dilution and interference from turbidity

78
Q

What is the other method (for hgb determination) that has been used in some automated instruments?

A

This other method involves the use of sodium lauryl sulfate (SLS) to convert hgb to SLS-methemoglobin

79
Q

What is the effect of the other method (for hgb determination | whereas it uses SLS)?

A

It is the method that does not generate toxic wastes

80
Q

What is hct?

A

It is the volume of PRBCs that occupies a given volume of WB

81
Q

Hct is often referred to as what?

A

Packed cell volume (PCV)

82
Q

How is hct reported?

A

It is reported either as:

1) Percentage (e.g., 36%)
2) / in liters per liter (0.36 L/L)

83
Q

What is the complete procedure of microhct?

A

1) Fill 2 plain capillary tubes approx 3 quarters full w/ bld anticoagulated w/ EDTA or heparin. Mylar-wrapped tubes are recommended by the National Institute for Occupational Safety and Health to reduce the risk of capillary tube injuries. Alternatively, bld may be collected into heparinized capillary tubes by skin puncture. Wipe any excess bld from the outside of the tube
2) Seal the end of the tube w/ the colored ring using nonabsorbent clay. Hold the filled tube horizontally and seal by placing the dry end into the tray w/ sealing compound at a 90-degree angle. Rotate the tube slightly and remove it from the tray. The plug should be at least 4 mm long
3) Balance the tubes in a microhct centrifuge w/ the clay ends facing the outside away from the center, touching the rubber gasket
4) Tighten the head cover on the centrifuge and close the top. Centrifuge the tubes at 10,000 g - 15,000 g for the time that has been determined to obtain maximum packing of RBCs. Do not use the brake to stop the centrifuge
5) Determine the hct by using a microhct reading device. Read the lvl of RBC packing; do not include the buffy coat (WBCs and PLTs) when taking the reading
6) The values of the duplicate hcts should agree within 1% (0.01 L/L)

84
Q

True or False

The time to obtain maximum packing of RBCs should not be determined for each centrifuge

A

False, because the time to obtain maximum packing of RBCs should be determined for each centrifuge

85
Q

What type of sx should be used for duplicate microhct determinations?

A

Fresh, well-mixed blood anticoagulated w/ EDTA

86
Q

How many sxs should be used for duplicate microhct determinations?

A

2

87
Q

Since 2 sxs should be used for duplicate microhct determinations, what should be the characteristic of 1 of the sxs?

A

1 of the sxs should have a known hct of 50% or higher

88
Q

At what time duration does centrifuge duplicate?

A

Starting at 2 mins (at 30-sec intervals), then record results

89
Q

When is the optimum packing (of RBCs) have been achieved?

A

When the hct has remained at the same value for 2 consecutive readings

90
Q

True or False

The 2nd time interval should be used for microhct determinations (for determining the maximum packing time for microhct)

A

True

91
Q

What are the components present in the capillary tube after centrifugation (in microhct determination)?

A

1) Plasma
2) Buffy coat (WBCs and PLTs)
3) RBCs

92
Q

What are the sources of error and comments (for microhct determination / reading)?

A

1) Improper sealing of the capillary tube causes a decreased hct reading as a result of leakage of bld during centrifugation. A higher # of RBCs are lost compared w/ plasma due to the packing of the cells in the lower part of the tube during centrifugation
2) An increased conc of anticoagulant (short draw in an etube) decreases the hct reading as a result of RBC shrinkage
3) A decreased / increased result may occur if the sx was not mixed properly
4) The time and speed of the centrifugation and the time when the results are read are impt. Insufficient centrifugation / a delay in reading results after centrifugation causes hct readings to increase. Time for complete packing should be determined for each centrifuge and rechecked at regular intervals. When the microhct centrifuge is calibrated, 1 of the sxs used must have a hct of 50% or higher
5) The buffy coat of the sx should not be included in the hct reading because this falsely elevates the result
6) A decrease / increase in the readings may be seen if the microhct reader is not used properly
7) Many disorders, such as sickle cell anemia, macrocytic anemias, hypochromic anemias, spherocytosis, and thalassemia, may cause plasma to be trapped in the RBC layer even if the procedure is performed properly. The trapping of the plasma causes the microhct to be 1 - 3% (0.01 - 0.03 L/L) higher than value obtained using automated instruments that calculate / directly measure the hct and are unaffected by the trapped plasma
8) A temporarily low hct reading may result immediately after a bld loss because plasma is replaced faster than are the RBCs
9) The fluid loss associated w/ dehydration causes a decrease in plasma volume and falsely increases the hct reading
10) Proper sx collection is an impt consideration. The introduction of interstitial fluid from a skin puncture / the improper flushing of an intravenous catheter causes decreased hct readings

93
Q

What are the characteristics of the READACRIT centrifuge (Becton, Dickinson and Company, Franklin Lakes, NJ)?

A

1) It uses precalibrated capillary tubes

2) It has built-in hct scales (w/c eliminates the need for separate reading devices)

94
Q

What is the effect of the use of SUREPREP capillary tubes (Becton, Dickinson)?

A

It eliminates the use of sealants (because they have a factory-inserted plug that seals automatically when the bld touches the plug)

95
Q

What is done when sxs are analyzed by automated / manual methods?

A

A quick visual check of the results of the hgb and hct can be done by applying the “rule of three”

96
Q

At what type of sxs does the rule of three only apply?

A

To sxs that have normocytic normochromic RBCs

97
Q

What should be the value of hct of sxs to apply the rule of three?

A

The value of hct should be 3 times the value of the hgb plus / minus 3 (HGB X 3 = HCT ± 3 [0.03 L/L])

98
Q

What should always be done by the analyst when applying the rule of three? Provide exs

A

It should become habit for the analyst to multiply the hgb by 3 mentally for every sx; a value discrepant w/ this rule may indicate abnormal RBCs, or it may be the 1st indication of error

Case 1 
   HGB = 12 g/dL 
   HCT = 36% (0.36 L/L) 
   Accdg to the rule of three, 
               HGB (12) X 3 = HCT (36) 
       An acceptable range for the hct would be 33 - 39%. These values conform to the rule of three

Case 2
HGB = 9 g/dL
HCT = 32%
Accdg to the rule of three,
HGB (9.0) X 3 = HCT (27 versus actual value of 32)
An acceptable range for hct would be 24 - 30%, so these values do not conform to the rule of three

Case 3
HGB = 15 g/dL
HCT = 36%
Accdg to the rule of three,
HGB (15) X 3 = HCT (45 versus obtained value of 36)
An acceptable range for hct would be 42 - 48%, so these values do not conform to the rule of three

99
Q

What are the things that should be done if values (via the rule of three) do not agree?

A

1) The blood film should be examined for abnormal RBCs

2) Causes of false increases and decreases in the hgb and/or hct values should also be investigated

100
Q

What does the bld film reveal (/ interpretation of the bld film) in the 2nd ex (/ 2nd case)?

A

The bld film reveals RBCs that are low in hgb conc (hypochromic) and are smaller in volume (microcytic), so the rule of three cannot be applied

101
Q

What should be done if RBCs do appear normal (in connection to the 2nd ex / case)?

A

Possible causes of falsely low hgb conc / a falsely elevated hct should be investigated

102
Q

What is determined in the sx in the 3rd ex (/ 3rd case)?

A

It is determined that the sx has lipemic plasma causing a falsely elevated hgb conc

103
Q

What is the resolution that must be done to the 3rd ex / case?

A

A correction must be made to obtain an accurate hgb value

104
Q

What should be done when an unexplained discrepancy is found (if the rule of three is applied)?

A

The sx processed before and after the sx in question should be checked to determine whether they conform to the rule

105
Q

What should be done if the resolution to assess an unexplained discrepancy is found is done, but they still not conform (if the rule of three is applied)?

A

If they do not conform, further investigation should be done to find the problem (a control sx should be run when such a discrepancy is found)

106
Q

What is the indication if the instrument produces appropriate results for the control (when a control sx is run)?

A

Random error may have occurred

107
Q

What are the RBC indices?

A

1) Mean cell volume (MCV)
2) Mean cell hemoglobin (MCH)
3) Mean cell hemoglobin concentration (MCHC)

108
Q

Why are the RBC indices calculated?

A

They are calculated to determine:

1) Ave volume of the RBCs (in the sx)
2) Hgb content
3) Conc of the RBCs (in the sx)

109
Q

What are the uses of RBC indices?

A

1) They may be used for initial classification of anemias

2) They may serve as a QC check

110
Q

Answer the ff questions w/ regards to the given RBC indices (at sp values):

1) What is the RBC morphology?
2) At what diseases / conditions are the value of RBC indices and the corresponding RBC morphologies found?

Given RBC indices (at sp values): MCV (fL): < 80; MCHC (g/dL): < 32

A

1) Microcytic; hypochromic

2) Iron deficiency anemia (IDA); anemia of inflammation; thalassemia; Hb E disease; and trait, sideroblastic anemia

111
Q

Answer the ff questions w/ regards to the given RBC indices (at sp values):

1) What is the RBC morphology?
2) At what diseases / conditions are the value of RBC indices and the corresponding RBC morphologies found?

Given RBC indices (at sp values): MCV (fL): 80 - 100; MCHC (g/dL): 32 - 36

A

1) Normocytic; normochromic

2) Hemolytic anemia; myelophthisic anemia; bone marrow failure; chronic renal disease

112
Q

Answer the ff questions w/ regards to the given RBC indices (at sp values):

1) What is the RBC morphology?
2) At what diseases / conditions are the value of RBC indices and the corresponding RBC morphologies found?

Given RBC indices (at sp values): MCV (fL): > 100; MCHC (g/dL): 32 - 36

A

1) Macrocytic; normochromic

2) Megaloblastic anemia; chronic liver disease; bone marrow failure; myelodysplastic syndrome

113
Q

What is MCV?

A

It is the average volume of the RBC

114
Q

MCV is expressed in what?

A

Femtoliters (fL) or 10^-15 L

115
Q

What is the formula for MCV?

A

HCT (%) X 10
MCV = ———————————-
RBC count (X 10^12/L)

116
Q

Provide an ex of computing MCV

A

Given values:

1) HCT = 45%
2) RBC ct = 5 X 10^12/L

MCV = 90 fL

117
Q

What is the reference interval for MCV?

A

80 - 100 fL

118
Q

What is the indication if RBCs have an MCV of < 80 fL?

A

These RBCs are microcytic

119
Q

What is the indication if RBCs have an MCV of > 100 fL?

A

These RBCs are macrocytic

120
Q

What is MCH?

A

It is the ave weight of hgb in a RBC

121
Q

MCH is expressed in what?

A

Picograms (pg) or 10^-12 g

122
Q

What is the formula for computing MCH?

A

HGB (g/dL) X 10
MCH = ———————————-
RBC count (X 10 ^12/L)

123
Q

Provide an ex of the computation of MCH

A

Given values:

1) HGB = 16 G/dL
2) RBC ct = 5 X 10^12/L

MCH = 32 pg

124
Q

What is the reference interval of MCH for adults?

A

26 - 32 pg

125
Q

True or False

MCH is generally considered in the classification of anemias

A

False, because MCH is generally not considered in the classification of anemias

126
Q

What is MCHC?

A

It is the ave conc of hgb in each individual RBC

127
Q

What are the units used for MCHC?

A

g/dL (formerly percentage)

128
Q

What is the formula for computing MCHC?

A

HGB (g/dL) X 100
MCHC = ————————-
HCT (%)

129
Q

Provide an ex of the computation of MCHC

A

Given values:

1) HGB = 16 g/dL
2) HCT = 48%

MCHC = 33.3 g/dL

130
Q

What is the range of MCHC for normochromic RBCs?

A

32 - 36 g/dL

131
Q

What is the range of MCHC for hypochromic RBCs?

A

< 32 g/dL

132
Q

What is the range of MCHC for hyperchromic RBCs?

A

> 36 g/dL

133
Q

What is the characteristic of the term “hyperchromic”?

A

It is a misnomer (because a cell does not really contain > 36 g/dL of hgb, but its shape may have become spherocytic, w/c makes the cell appear full)

134
Q

What should be done to an MCHC between 36 and 38 g/dL?

A

It should be checked for spherocytes

135
Q

What should be done to an MCHC > 38 g/dL?

A

It should be investigated for an error in hgb value

136
Q

What could be the other cause for a markedly increased MCHC?

A

It could be the presence of a cold agglutinin

137
Q

What is the resolution that should be done if the cause for a markedly increased MCHC could be the presence of a cold agglutinin?

A

Incubating the sx at 37 DC for 15 mins before analysis usually produces accurate results

138
Q

What is a reticulocyte?

A

It is the last immature RBC stage

139
Q

What are the normal characteristics of reticulocytes?

A

1) They spend 2 days in the bone marrow
2) & they spend 1 day in the peripheral bld (before developing into a mature RBC)
3) It contains:
a. Cytoplasmic ribonucleic acid (RNA)
b. Organelles
i. Mitochondria
ii. Ribosomes
4) They are any nonnucleated RBC
5) They contain 2 / more particles of blue-stained granulofilamentous material (after new methylene blue staining | / blue-stained filaments / particles)

140
Q

What is the use of reticulocyte ct?

A

It is used to assess the erythropoietic activity of the bone marrow

141
Q

What is the principle (/ procedure) of reticulocyte ct?

A

WB (anticoagulated w/ EDTA), is stained w/ a supravital stain (such as new methylene blue)

142
Q

What is the complete procedure of reticulocyte ct?

A

1) Mix equal amts of bld and new methylene blue stain (2 - 3 drops, or approx 50 uL each), and allow to incubate at room temp for 3 - 10 mins
2) Remix the preparation
3) Prepare 2 wedge films
4) In an area in w/c cells are close together but not touching, ct 1000 RBCs under OIO lens (1000x total magnification). Retics are included in the total RBC ct (i.e., a retic cts as both an RBC and a retic)
5) To improve accuracy, have another laboratorian ct the other film; cts should agree within 20%
6) Calculate the % retic ct:
number of reticulocytes X 100
Reticulocytes (%) = ——————————————-
1000 (RBCs counted)

143
Q

Provide an ex of the computation of retics

A

Given value:
1) Retics cted: 15

                            15 X 100  Reticulocytes (%) = ------------- 
                                1000
                         = 1.5%

Or the # of retics cted can be multiplied by 0.1 (100/1000) to obtain the result

144
Q

True or False

Large #s of RBCs should be cted to obtain a more precise retic ct

A

True

145
Q

Since large #s of RBCs should be cted to obtain a more precise retic ct, what instrument should be used?

A

Miller disc

146
Q

What is the use of Miller disc?

A

To reduce the labor-intensive process

147
Q

What is the composition of the Miller disc?

A

It is composed of 2 squares (the area of the smaller square measures 1/9 the area of the larger square | there are 2 squares [1 small square + 1 big square])

148
Q

Where is the Miller disc inserted?

A

It is inserted into the eyepiece of the microscope and the grid (/ Miller ocular disc counting grid) is seen

149
Q

In the Miller ocular disc cting grid, where are RBCs cted?

A

In the smaller square

150
Q

In the Miller ocular disc cting grid, where are retics cted?

A

In the larger square

151
Q

How many cells should be cted in the small square (in the Miller ocular disc cting grid)?

A

Minimum of 112 cells

152
Q

What are the reasons why are a minimum of 112 cells should be cted in the small square (in the Miller ocular disc cting grid)?

A

1) Because this is equivalent to 1008 RCs in the large square
2) Because it satisfies the CAP hematology std for a manual retic ct based on at least 1000 RCs

153
Q

What is the meaning of CAP?

A

College of American Pathologists

153
Q

What is the formula for calculating percent retics?

A

no. of reticulocytes in square A
(large square) X 100
Reticulocytes (%) = ——————————————————
no. RBCs in square B (small square) X 9

154
Q

Provide an ex of computation of retics

A

Given value:

1) # of retics cted (in the large square): 15
2) RBCs cted (in the small square): 112

                           15 X 100 Reticulocytes % = -------------
                            112 X 9  
                        = 1.5%
155
Q

What are the sources of error and comments for retic ct?

A

1) If a pt is very anemic / polycythemic, the proportion of dye to bld should be adjusted accordingly
2) An error may occur if the bld and stain are not mixed before the films are made. The SG of the retics is lower than that of mature RBCs, and retics settle at the top of the mixture during incubation
3) Moisture in the air, poor drying of the slide, / both may cause areas of the slide to appear refractile, and these areas could be confused w/ retics. The RNA remnants in a retic are not refractile
4) Other RBC inclusions that stain supravitally include Heinz, Howell-Jolly, and Pappenheimer bodies. Heinz bodies are precipitated hgb, usually appear round / oval, and tend to adhere to the cell membrane. Howell-Jolly bodies are round nuclear fragments and are usually singular. Pappenheimer bodies are iron in the mitochondria whose presence can be confirmed w/ an iron stain, such as Prussian blue
5) If a Miller disc is used, it is impt to heed the “edge rule” as described in the WBC ct procedure. A significant bias is observed if the rule is ignored

156
Q

What are the other RBC inclusions that stain supravitally?

A

1) Heinz bodies
2) Howell-Jolly bodies
3) Pappenheimer bodies

157
Q

What are the characteristics of Heinz bodies?

A

1) These usually appear round / oval

2) These tend to adhere to the cell membrane

158
Q

What are the characteristics of Howell-Jolly bodies?

A

1) These are round nuclear fragments

2) These are usually singular

159
Q

What is absolute reticulocyte count (ARC)?

A

It is the actual # of retics in 1 L / 1 uL of bld

160
Q

What is the formula for computing ARC?

A

reticulocytes (%) X RBC count (X 10^12/L)
ARC = ————————————————————
100

161
Q

Provide an ex of computing ARC

A

Given values:

1) Retic ct: 2%
2) RBC ct: 2.20 X 10^12/L

       2 X (2.20 X 10^12/L) ARC = -------------------------------
                      100 
     = 44 X 10^9/L

Note: the calculated result has to be converted from 10^12/L to 10^9/L

ARC can also be reported as the number of cells/uL. Using the ex above, the RBC ct in uL (2.20 X 10^6/uL) is used in the formula, and the ARC result is 44 X 10^3/uL

162
Q

What is the reference interval / value for ARC?

A

20 X 10^9/L - 115 X 10^9/L (for most populations)

163
Q

What is the status of the percentage of retics in sxs w/ a low hct (in connection w/ corrected reticulocyte count [CRC])?

A

The percentage of retics may be falsely elevated

164
Q

Why is the percentage of retics may be falsely elevated in sxs w/ a low hct (in connection w/ CRC)?

A

Because the WB contains fewer RBCs

165
Q

What is the variable used in CRC?

A

Correction factor

166
Q

What should be the ave normal hct?

A

It is considered to be 45%

167
Q

What is the formula for computing CRC?

A

Corrected reticulocyte count (%) = reticulocyte (%) X patient HCT (%)
———————-
45

168
Q

In terms of reference interval (of CRC), what should be the CRC of pts w/ a hct of 35% and why?

A

They should have an elevated CRC of 2 - 3% (to compensate for the mild anemia)

169
Q

In terms of reference interval (of CRC), what should be the CRC of pts w/ a hct of < 25% and why?

A

The ct should increase to 3 - 5% (to compensate for the moderate anemia)

170
Q

The CRC depends on what?

A

It depends on the degree of anemia

171
Q

What are shift retics (in connection w/ the principle of reticulocyte production index)?

A

These are retics that are released from the marrow prematurely

172
Q

What is the principle of shift retics?

A

These retics are “shifted” from the bone marrow to the peripheral bld earlier than usual to compensate for anemia

173
Q

How many days does shift retics take to lose their reticula?

A

Instead of losing their reticulum in 1 day, as do most normal circulating retics, these cells take 2 - 3 days to lose their reticula

174
Q

What should be done if erythropoiesis is evaluated (in connection w/ the principle of retic production index)?

A

A correction should be made for the presence of shift retics if polychromasia is reported in the RBC morphology

175
Q

When and how are most normal (nonshift) retics become mature RBCs (in connection w/ the principle of retic production index)?

A

Within 1 day after entering the bldstream and thus represent 1 day’s production of RBCs in the bone marrow

176
Q

What is the characteristic of cells shifted to the peripheral bld?

A

These cells prematurely stay longer as retics

177
Q

What is the action of the cells shifted to the peripheral bld (in connection w/ the principle of retic production index)?

A

They contribute to the retic ct for more than 1 day

178
Q

Due to the characteristic and action of the cells that are shifted to the peripheral bld, what is their effect to retic ct (in connection w/ the principle of retic production index)?

A

The retic ct is falsely increased when polychromasia is present (because the ct no longer represents the cells maturing in just 1 day)

179
Q

True or False

On many automated instruments, the mathematical adjustment of the retic ct has been replaced by the measurement of immature retic fraction

A

True

180
Q

True or False

The pt’s hct is used to determine the appropriate correction factor (retic maturation time in days)

A

True

181
Q

What is the correction factor (maturation time, days [/ in days]) for the given pt’s hct value (%)?

Given pt’s hct value: 40 - 45

A

1

182
Q

What is the correction factor (maturation time, days [/ in days]) for the given pt’s hct value (%)?

Given pt’s hct value: 35 - 39

A

1.5

183
Q

What is the correction factor (maturation time, days [/ in days]) for the given pt’s hct value (%)?

Given pt’s hct value: 25 - 34

A

2

184
Q

What is the correction factor (maturation time, days [/ in days]) for the given pt’s hct value (%)?

Given pt’s hct value: 15 - 24

A

2.5

185
Q

What is the correction factor (maturation time, days [/ in days]) for the given pt’s hct value (%)?

Given pt’s hct value: < 15

A

3

186
Q

What is the formula for computing reticulocyte production index (RPI)?

A

reticulocyte (%) X [HCT (%)/45]
RPI = ——————————————–
maturation time

Or

      corrected reticulocyte count RPI = --------------------------------------------
                maturation time

Hematology 1 (Laboratory) (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions