Laboratory Sample Handling Flashcards
6 cards from real CVA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Laboratory Sample Handling flashcards as text
What is the correct method for preparing a blood smear for differential WBC count?
Answer: Place a small drop near one end, use a spreader slide at 30-45 degrees to push forward in one smooth motion
A proper wedge smear uses a small drop and a spreader slide at 30-45 degrees, creating a feathered edge where cells are in a monolayer.
Which urine collection method provides the most sterile sample for bacterial culture?
Answer: Cystocentesis
Cystocentesis bypasses the urethra and external genitalia entirely, providing the least contaminated sample for culture.
Why must blood collection tubes be filled to the proper volume?
Answer: Improper blood-to-anticoagulant ratio affects test accuracy, especially coagulation assays
Tubes are calibrated for specific blood-to-additive ratios. Underfilling causes excess anticoagulant, significantly affecting coagulation times.
What does lipemia mean when noted on a blood sample?
Answer: Cloudiness of serum due to elevated triglycerides, usually from a non-fasted sample
Lipemia refers to turbidity caused by elevated triglycerides and lipoproteins, most commonly from blood drawn from a non-fasted patient.
When performing a fecal flotation, what specific gravity should the flotation solution have?
Answer: 1.18-1.20
Most common parasite eggs have specific gravity 1.05-1.15, so a solution of 1.18-1.20 allows them to float while debris sinks.
What is the significance of the buffy coat layer in a microhematocrit tube?
Answer: It represents packed white blood cells and platelets between plasma and red cell layers
The buffy coat is the thin whitish layer consisting of WBCs and platelets, and its thickness provides a rough estimate of WBC count.