PCV, Total Solids, Fibrinogen

What are three reasons to make 2-4 hematocrit tubes?

Not enough plasma for total solids, tubes damaged in centrifuge, tubes breaking at the wrong point

A measure of the percentage of blood comprised of packed RBCs

Packed Cell Volume/ Hematocrit

What are the three components of PCV?

Red blood cells, buffy coat (WBCs and platelets), Plasma

How should a hematocrit tube be centrifuged?

10,000 rpm for 5 minutes

Normal plasma color for most mammals

Clear to straw

A pink or red plasma would indicate…?

Hemolysis due to patient or technique

Yellow plasma would indicate…?

Icteric (jaundice)

*Normal for horses and cows

Milky/Cloudy plasma would indicate…?

Lipemia (fat in the blood)

Measure of the total protein content (including clotting factors) in the blood

Total Solids/Total Protein

How are total solids recorded?

g/dL

Which tool is used to read total solids?

Refractometer

The measure of clotting factors in plasma

Fibrinogen

What is the procedure for reading fibrinogen?

1. Centrifuge as for PCV

2. Obtain PCV and TS readings from two of the tubes

3. Incubate remaining two tubes at 58 degrees C for 3-5 minutes

4. Recentrifuge

5. Read as if performing TS

What is the calculation for determining fibrinogen?

Total solids reading (g/dl) - Incubated TS reading (g/dl) = *1000 = Fibrinogen (mg/dl)

What is the RBC Count estimation equation?

RBC = (PCV/6) = RBC * 10^6 cells/ul

WBC Count Estimation equation

Measure buffy coat. 1mm = 10,000 cells/ul

Each 0.1 mm after = 2,000 cells/ul

Hemoglobin estimation equation

Hemoglobin (g/dl) = (PCV/3)

How can microfilaria be identified on PCV tube?

Place tube on microscope and focus on low power, then switch to high power

Use low light

Microfilaria will wiggle and “Dance” just above the buffy coat