HEM Manual Methods Flashcards
PB smears need at least _ identifiers
PB smears need at least TWO identifiers: name and accession
T or F: WBC diff and RBC morph is performed on albumin smears
FALSE; only WBC diffs are performed on albumin smears
Samples with __ Hgb should dry longer to prevent water artifact
Samples with LOW Hgb (thin blood) should dry longer to prevent water artifact
For malarial studies on a PB smear, what is checked when samples is received ?
- patient history to check previous positives / abnormal results
- determine whether initial exam or follow-up of treatment
- new positive = PATHOLOGIST NOTIFIABLE
MALarial protocol requires what/ how many smears ?
- 4 thin smears; 2 stained/ unstained
- 4 thick smears; all two-drop smears, unstained
What is a buffy coat smear for ?
- a concentrated cell prep when WBC count is too low for routine
- evaluates WBC morph + bacteria/ parasites queried on the PB smear
T or F: It is acceptable if buffy coat smear has RBCs
TRUE; It is acceptable if buffy coat smear has RBCs
Which stain is used for malaria ?
Giemsa stain
Which stain is used to demonstrate iron stores in bone marrows smears ?
Prussian Blue Iron stain:
- iron deposits are inside cells; extracellular iron is considered artifacts
Components of Wright-Giemsa Stain (Romanowsky)
- methylene blue + azure B (basic dyes) stain acidic RNA + DNA
- eosin (acidic dye) stains basic Hgb + eosinophils
Formula: WBC correction for presence of nRBC
[Automated WBC x 100] / (100 + nRBC)
Formula: Relative Retic Count
[#retics on slide 1 + #retics on slide 2]/ (500 + 500)
NOTE: up to ~500 RBCS are counted for each slide by separate techs
How is a fluid count performed when there are crystals present?
- 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)
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
b.
Brilliant green stain
ESR Principle
- 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
Manual CSF Cell Count: If <200 RBC/WBCs in all 9 squares, then..
count RBC/ WBCs in all 9 squares
Manual CSF Cell Count: If >200 in all 9 squares, then..
count RBC/ WBCs in 4 corner squares labeled “W”
Manual CSF Cell Count: If >200 RBC/ WBCs in 1 of 9 squares, then..
count RBC/ WBCs in 5 center small squares labeled “R”
Which cells are reported in CSF ?
RBCs and WBCs
Xanthochromia
Yellow or orange discoloration of CSF
Lymphocytes can be increased in this type of infection
Viral Infections
__ and __ can cause a cloudy CSF sample
HIGH WBC COUNT and MICROORGANISMS can cause a cloudy CSF sample
What is used to dilute a CSF when performing the nucleated cell count?
Acetic Acid
May-Grunwald components of MGG stain
Methylene blue, eosin
Components primarily stained by MGG
Cytoplasmic components
Basic components of Wright-Giemsa
Methylene blue, azure B
Stained by basic dyes
DNA/RNA
Increased in pH during staining causes RBC to appear what color ?
Blue-green
What do these stains all have in common:
Methyl Violet, Brilliant Cresyl Blue, Crystal Violet, Brilliant Green
All SUPRAVITAL STAINS
Formula: %Parasitemia
(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 …
