(M) Week 7: CBC and other procedures I part 2 Flashcards
familiarize the reagents and equipment for blood smear
- slides
- hematological stains
- microscope
- schilling counter
what are the stains used in differential counts
- Wright’s
- Giemsa
- Leishman’s
- other romanowsky stain
Romanowsky stain’s dip method uses which reagents
a. methanol (fixative for blood smear)
b. eosin (primary stain)
c. methylene blue (secondary stain)
d. distilled water (washes out excess stain)
rack method
stains that are too acidic changes the __________ or the ____________ of the cell
appearance or morphology of the cell
rack method
stains that are too acidic changes the cell color to
bright red or pink
rack method
stains that are too basic or alkaline can appear (darker / lighter in color)
darker
rack method
what helps maintain the integrity of the blood smear
washing
what type of microscope is used for differential count
bright-field
what type of Romanowsky stain is routinely used
Wright’s
which type of Romanowsky stain is used in searching for malarial parasites
Giemsa
What causes falsely increased WBC when the patient is crying?
WBC in the marginating pool migrates to the circulating pool
familiarize the procedure
- check slide identification
- perform patient specimen orientation
- perform low power scan to review blood film adequacy
- perform diff leukocyte count
- classify 100 leukocytes using the battlement track method
- report results of the 100 cells classified as percentage
- keep separate count of nucleated RBCs
- Note and report the abnormal leukocyte morphology
- Identify and report any miscellaneous non-leukocyte abnormal cells such as endothelial cells, basket cells, or NRBCs
in what areas of the smear do we perform cell counting?
uniform monolayer of smear
What are the criteria for leukocyte identification
- cell size
- nuclear - cytoplasmic ratio
- cytoplasmic characteristics
- nuclear characteristics
what does high NC ratio mean in leukocyte identification
immature cell
(nucleus occupies most cell areas with only a small rim)
what does low NC ratio mean in leukocyte identification
mature cell
nucleus is small in relation to volume of cytoplasm
what are the three cytoplasmic characteristics
a. color of background cytoplasm
b. presence of absence of granules
c. color and size of granules
what are the nuclear characteristics
- shape
b. color
c. chromatin pattern
d. presence or absence of nucleus
neutrophil with more than 5 lobules
hypersegmented
neutrophil with less than 3 lobules
hyposegmented
sign of maturation in neutrophil
conspicuous filament / constrictioni that connects segments
an immature neutrophil (no restriction)
- c or s shaped
band neutrophil
there is a slight indentation, kidney bean-shaped with lilac granules
metamyelocyte
has fine chromatin sturcture and uniform nucleus, cytoplasm appears sky blue in color
lymphocytes
what is the sign of maturation for lymphocytes
granules
what are the sizes of lymphocytes
small, medium, and large
this WBC has frosted glass appearance, kidney bean shaped with rough nucleus
monocyte
what is the largest cell in circulation
monocyte
which has the least number among all the WBCs
basophils
WBC with highly intense granules that appear blue to black in color, may undergo degranulation (in allergic reactions)
basophil
normal reference value for WBCs from most concentrated to least concentrated
NEVER LET MONKEY EAT BANANA
neutrophil
lymphocyte
monocyte
eosinophil
basophil
stab/ band cell
what is the normal reference value for neutrophil
47-49
what is the normal reference value for lymphocyte
14-47
what is the normal reference value for monocyte
2-11
what is the normal reference value for eosinophil
0-7
what is the normal reference value for basophil
0-2
what is the normal reference value for stab / band cell
0-7
this provides the number of specific WBC type per cubic millimeter of blood
absolute count
T or F
relative count is more informative than absolute count
f (absolute count)
what is the formula for the absolute count
relative count (%) x WBC count
please check out the normal reference value for absolute counte
edi dont
familiarize the irregularities in blood smear preparation affecting leukocytes
- squashed / distorted lymphocytes
- accumulated white cells
- smudge cells
- disintegrated or ruptured cells
- poorly stained leukocytes
- precipitated stain
these causes which type of irregularity in blood smears
- incorrect pH or buffer
- improper mixing of stain and buffer
- too short staining period
poorly stained leukocytes
when should 200-differential be performed?
when leukocyte number is in excess of 35.0 X 10^9 / L
What should be used if WBC count is less than 1.0 x 10^9
buffy coat smear
When using a high power objective, how is WBC count done?
scan the smear and average the WBCs per field
platelet estimate:
starting from normal upwards just (subtract / add) _______________
From marked decreased to normal
subtract 50,000
platelet estimate:
starting from normal downwards just (subtract / add) _______________
From normal to marked increase
add 200,000
platelet estimate reporting:
0-49,000 /uL
marked decrease
platelet estimate reporting:
50,000 - 99,000 / uL
moderately decrease
platelet estimate reporting:
100,000 - 149,000 / uL
slightly decrease
platelet estimate reporting:
150,000 -199,000 /uL
low normal
platelet estimate reporting:
200,000 to 400,000 / uL
normal
platelet estimate reporting:
401,000 - 599,000 / uL
slightly increase
platelet estimate reporting:
600,000 - 800,000 / uL
moderately increased
platelet estimate reporting:
above 800,000 /uL
marked increase
this is the number of platelets in 1L or 1mL of whole blood
platelet count
platelets are counted in the ____________ in the large center square of the hemacytometer
25 small squares
what microscope is used to count platelets in the hemacytometer?
phase-contrast microscope or Bright-field microscope
what type of microscope is used in the Brecher and Cronkite method of platelet count?
phase-contrast microscope
what type of microscope is used in the Rees and Ecker method of platelet count
bright-field microscope
Which methods fall under the Manual indirect method of platelet counting?
Fonio’s
Olef’s
Dameshek
Which methods fall under the Manual direct method of platelet counting?
Guy and Leake
Rees and Ecker
Brecher and Cronkite
Which methods fall under the electronic method of platelet counting
voltage-pulse counting
electro-optical counting
In Fonio’s method in manual indirect platelet count, where is the diluting fluid placed?
site of puncture
what is the diluting fluid for Fonio’s method
magnesium sulfate
what is the ratio of blood to diluent in Fonio’s Method?
1 part blood : 5 parts magnesium sulfate
how many RBCs should be counted in Fonio’s method
1000
what is considered as the best indirect method of platelet counting
Olef’s method
Confirmation of the platelet count is done on the bases of _____________________ in the peripheral smear
occurrence of platelets
Olef’s method reporting:
5 to 20 platelets / OIO field (with occasional clumping)
adequate supply of platelets
Olef’s method reporting:
> 25 platelets / OIO field
increase in the number of platelets
what are the diluents used in Dameshek’s method
brilliant cresyl blue
sodium citrate
sucrose
formalin
dameshek’s method uses the same technique as
Fonio’s
what is the counterstain for Dameshek’s method
Wright’s stain
what is the formula for calculation for platelets
platelets / uL = platelet x RBC count / 1000
What is the equipment used in direct methods in platelet counting
hemocytometer
Which direct method in platelet counting utilizes a diluent composed of :
sodium oxalate
40% formalin
crystal violet
Guy and Leake
Which one is more accurate?
direct vs indirect methods of platelet counting
direct
Which methods fall under the Manual direct method of platelet counting:
sodium oxalate
brilliant cresyl blue
formalin
distilled water
Rees and ecker
what is the calculation for guy and leake
platelet/uL = platelet counter x 5 (area of square counted) x 10 (depth of counting chamber) x 100 (dilution factor)
what is the formula for Rees and Ecker?
platelets / uL = platelets counted x 10 x 200 /4
What is the platelet calculation formula for Dameshek’s method
platelet x RBC / 1000
What is the platelet calcularion for Brecher and Cronkite?
same as Guy and Leake
platelet/uL = platelet counter x 5 (area of square counted) x 10 (depth of counting chamber) x 100 (dilution factor)
platelets are stained _____________ in Rees and Ecker’s method
light blue
what is the percent error in Brecher and Cronkite’s method
11-15%
what is the microscope used for brecher and cronkite
phase contrast microscope
what is the diluent for Brecher and Cronkite
1% ammonium oxalate
This is the most accurate method because there is no difficulty in distinguishing platelets from debris because the diluting fluid swells the platelet a little and hemolyze the red cells
Brecher and Cronkite
What is the formula for Brecher and Cronkite
platelet x 5 x 10 x 100
What should be done first in the Electronic method in platelet counting
red cells must be removed from whole blood (either via sedimentation or centrifugation)
What is the dilution for Voltage-Pulse counting
1:3000 (3uL blood + 9mL isotonic NSS)
What is the diluent in Voltage-pulse counting
iosotonic NSS
Voltage-Pulse counting
If the platelet count is less than 250,000 /uL what should be the dilution instead?
1:300 (20uL blood / 6mL diluent)
what is the principle used in Voltage-Pulse counting
electronic impedance
what is the dilution in electro-optical counting
1:1500
what is the diluent for electro-optical counting
2M Urea
Electro-optical counting
these 2 are observed in some patients’ EDTA treated blood
platelet satellitosis
platelet clumping
what should be done to resolve platelet satellitosis
redraw the blood to sodium citrate and multiply platelet count result to 1.1
this is due to a type of agglutinin found in the patient at a certain temperature, may occur in cases of poor venipuncture
platelet clumping
Unopette system
this is where sample is obtained
reservoir
Unopette system
you need to puncture _________________ using the tip of the pipette to facilitate the flow of the sample to the counting chamber
diaphram
familiarize:
reasons why platelets are hard to count
- easily disintegrate / lyse
- small size, mistaken for debris
- easily clumps and adhere to glass and other contact surfaces
- uneven distribution of the blood
Familiarize;
sources of error in platelet counting
- error in handling
- operator’s error
- error in equipment and reagent
- inherent error and field error
Familiarize:
cases of platelet clumping
- initiation of plt aggregation
- clotting before blood reaches the anticoagulant
- imperfect venipuncture
- delay in sampling
platelet count is slightly (lower / higher) at birth than in older children and adults
lower
