# Hematology 1 & 2

WBC DIFFERENTIAL

measure of the percentage of different types of white blood cells present in the bloodOBTAINED BY:1. AUTOMATED CBC (LAB MACHINE) 2. MANUAL COUNT (HEMACYTOMETER)

DETERMINING THE ABSOLUTE COUNT

EXAMPLE:TWBCC WAS 10,000YOU COUNTED 80 NEUTROPHILS1. YOUR COUNT IS A PERCENTAGE SEEN →→→→ 80 = 80%2. CONVERT INTO RELATIVE COUNT (A DECIMAL)→→ 80% ÷ 100 = 0.83. MULTIPLY RELATIVE COUNT BY TWBCC→→→ 0.8 X 10,000 = 8,000ABSOLUTE COUNT FOR NEUTROPHILS = 8000 NEUTROPHILS/UL

PLATELET COUNTING (ESTIMATE)

• Count after WBC's counted• Focus in thicker layer (RBC touching)• Procedure:1. Count platelets in 10 fields2. Average the 10 fields3. Divide total number by 104. Multiply average number by 15,000 = estimated platelets/ uL❖ 15,000 same as 15 x 103

CORRECTED WBC COUNT

• WBC differential = count all nucleated cells• Correct WBC count only if >10 nRBC counted• Procedure:1. Perform a 100 cell differential as usual2. Count total # of nRBC seen during 100 cell count3. Follow formula:100 WBCs × total WBC count/100 WBCs + # nRBCs = # WBC/uL

Packed Cell Volume (PCV)

(also, hematocrit) volume percentage of erythrocytes present in a sample of centrifuged blood

Estimated Hemoglobin (Hb)

PCV / 3 = Estimated Hb

Refractometer

Instrument that measures specific gravity

Total Protein (TP)

How to:• Use HCT tubes from PCV• Break HCT tube just above buffy coat• Allowplasmatoflowonto refractometer• Read TP concentration in g/dL at horizon. Use TP, SP, or TS scale.• Normals:• K9=5.4-7.7g/dL• Feline = 5.6-7.7 g/dL