Benign Heme

Question 1

What are the measured CBC parameters

Answer 1

Hgb, RBC, MCV, RDW

Question 2

If a sample is hemolyzed on receipt, is the Hgb valid?

Answer 2

Yes. Hemolyzing is the first step in measuring Hgb.

Question 3

What are the 3 methods used to perform cell counts?

Answer 3

1. Impedance
2. Optical
3. Combination of impedance and optical

Question 4

What method is used to count RBC

Answer 4

Coulter principle

Question 5

What is impedance

Answer 5

Impedance is when cells travel through an aperture across which a current is flowing, causing a momentary increase in impedence/electrical resistance

Question 6

What is the formula for impedance

Answer 6

V=IR

voltage=current X resistance

Question 7

What is the size of particles counted as RBCs in a RBC cell count

Answer 7

36-360fL

Question 8

What are the 3 calculated CBC parameters

Answer 8

Hct
MCH
MCHC

Question 9

What are the most neoplastic common causes for increased RBC count (mimics PV)

Answer 9

RCC
HCC
hemangioblastoma

Question 10

How is WBC count performed

Answer 10

Lyse all RBC, then count all cells over 36 fL (platelets usually 2-20fL)

Question 11

What are some WBC interferences

Answer 11

Platelet clumps, micromegakaryocytes, nRBCs

Question 12

What is a troubleshooting method for platelet satellitism/clumping

Answer 12

For plt clumping, recollect in sodium citrate and multiply plt count by 1.1 to correct for dilution factor