HEM Manual Methods

Question 1

PB smears need at least _ identifiers

Answer 1

PB smears need at least TWO identifiers: name and accession

Question 2

T or F: WBC diff and RBC morph is performed on albumin smears

Answer 2

FALSE; only WBC diffs are performed on albumin smears

Question 3

Samples with __ Hgb should dry longer to prevent water artifact

Answer 3

Samples with LOW Hgb (thin blood) should dry longer to prevent water artifact

Question 4

For malarial studies on a PB smear, what is checked when samples is received ?

Answer 4

• patient history to check previous positives / abnormal results
• determine whether initial exam or follow-up of treatment
• new positive = PATHOLOGIST NOTIFIABLE

Question 5

MALarial protocol requires what/ how many smears ?

Answer 5

• 4 thin smears; 2 stained/ unstained
• 4 thick smears; all two-drop smears, unstained

Question 6

What is a buffy coat smear for ?

Answer 6

• a concentrated cell prep when WBC count is too low for routine
• evaluates WBC morph + bacteria/ parasites queried on the PB smear

Question 7

T or F: It is acceptable if buffy coat smear has RBCs

Answer 7

TRUE; It is acceptable if buffy coat smear has RBCs

Question 8

Which stain is used for malaria ?

Answer 8

Giemsa stain

Question 9

Which stain is used to demonstrate iron stores in bone marrows smears ?

Answer 9

Prussian Blue Iron stain:
- iron deposits are inside cells; extracellular iron is considered artifacts

Question 10

Components of Wright-Giemsa Stain (Romanowsky)

Answer 10

• methylene blue + azure B (basic dyes) stain acidic RNA + DNA
• eosin (acidic dye) stains basic Hgb + eosinophils

Question 11

Formula: WBC correction for presence of nRBC

Answer 11

[Automated WBC x 100] / (100 + nRBC)

Question 12

Formula: Relative Retic Count

Answer 12

[#retics on slide 1 + #retics on slide 2]/ (500 + 500)

NOTE: up to ~500 RBCS are counted for each slide by separate techs

Question 13

How is a fluid count performed when there are crystals present?

Answer 13

• Interfering substances requires a manual fluid cell count
• Sample can be diluted using acetic acid to lyse all RBC as only WBC are reported (unless RBC are specified on requisition)

Question 14

Which of the following can be used to demonstrate heinz bodies?

a.
Prussian blue stain

b.
Brilliant green stain

c.
Wright’s stain

d.
May-Grunwald-Giemsa stain

Answer 14

b.
Brilliant green stain

Question 15

ESR Principle

Answer 15

• non-specific test for inflammation (Acute Phase Reactants; APR)
• increased APR (proteins) = reduced zeta potential = RBCs stack faster
• blood settles in Westergren tubes for 1 hour
• measures distance from bottom of plasma meniscus to the sediment RBCs (mm)

NOTE: ESR is now replaced with CRP testing

Question 16

Manual CSF Cell Count: If <200 RBC/WBCs in all 9 squares, then..

Answer 16

count RBC/ WBCs in all 9 squares

Question 17

Manual CSF Cell Count: If >200 in all 9 squares, then..

Answer 17

count RBC/ WBCs in 4 corner squares labeled “W”

Question 18

Manual CSF Cell Count: If >200 RBC/ WBCs in 1 of 9 squares, then..

Answer 18

count RBC/ WBCs in 5 center small squares labeled “R”

Question 19

Which cells are reported in CSF ?

Answer 19

RBCs and WBCs

Question 20

Xanthochromia

Answer 20

Yellow or orange discoloration of CSF

Question 21

Lymphocytes can be increased in this type of infection

Answer 21

Viral Infections

Question 22

__ and __ can cause a cloudy CSF sample

Answer 22

HIGH WBC COUNT and MICROORGANISMS can cause a cloudy CSF sample

Question 23

What is used to dilute a CSF when performing the nucleated cell count?

Answer 23

Acetic Acid

Question 24

May-Grunwald components of MGG stain

Answer 24

Methylene blue, eosin

Question 25

Components primarily stained by MGG

Answer 25

Cytoplasmic components

Question 26

Basic components of Wright-Giemsa

Answer 26

Methylene blue, azure B

Question 27

Stained by basic dyes

Answer 27

DNA/RNA

Question 28

Increased in pH during staining causes RBC to appear what color ?

Answer 28

Blue-green

Question 29

What do these stains all have in common:
Methyl Violet, Brilliant Cresyl Blue, Crystal Violet, Brilliant Green

Answer 29

All SUPRAVITAL STAINS

Question 30

Formula: %Parasitemia

Answer 30

(no. Of parasitized RBCs in small square A) / (no. RBCs in large square B) x (100 / 9)*

NOTE: Count all RBCs in square B, for a total of 111 RBCs

*100/9 = 11.111 …