CVA Laboratory Techniques and Diagnostic Procedures 3

Question 1

Which anticoagulant is used in a purple-top (EDTA) tube and works by chelating calcium?

Accepted Answer

EDTA (ethylenediaminetetraacetic acid)

Answer

EDTA chelates (binds) calcium ions, preventing the coagulation cascade from activating, making purple-top tubes ideal for CBCs.

Question 2

When performing a urine specific gravity measurement with a refractometer, what solution is used to calibrate the instrument?

Accepted Answer

Distilled water

Answer

Distilled water reads 1.000 on a refractometer, making it the correct calibration standard for urine specific gravity.

Question 3

A fecal flotation uses a solution with a specific gravity higher than parasite eggs to do what?

Accepted Answer

Cause eggs to float to the surface for collection

Answer

High specific gravity flotation solutions are denser than parasite eggs, causing the eggs to rise and concentrate at the liquid surface under a coverslip.

Question 4

Which cell type, elevated in a CBC differential, is most commonly associated with allergic reactions and parasitic infections?

Accepted Answer

Eosinophils

Answer

Eosinophilia is classically linked to hypersensitivity (allergic) responses and parasitic infestations.

Question 5

What is the correct order of layers from top to bottom after centrifuging a hematocrit tube?

Accepted Answer

Plasma, buffy coat, packed red blood cells

Answer

After centrifugation, plasma (least dense) sits on top, the buffy coat (WBCs/platelets) is in the middle, and packed RBCs (most dense) are at the bottom.

(CVA) Certified Veterinary Assistant Practice Test

(CVA) Certified Veterinary Assistant Practice Test

CVA Laboratory Techniques and Diagnostic Procedures 3