Specimen Processing and Handling Flashcards
7 cards from real Phlebotomy Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Specimen Processing and Handling flashcards as text
Which condition causes a specimen to appear lipemic, and how does it affect test results?
Answer: High lipid content causing milky turbidity; can interfere with photometric assays
Lipemia from elevated triglycerides creates turbid, milky plasma or serum that scatters light and can interfere with spectrophotometric laboratory measurements.
The order of draw for a PST (plasma separator tube) relative to a red-top tube when drawing multiple tubes is:
Answer: Red-top first, then PST
Following standard order of draw, non-additive tubes (red-top) are collected before additive tubes such as PST to avoid contaminating the serum specimen with anticoagulant carryover.
A clot forms in an EDTA tube submitted for a CBC. The MOST likely cause is:
Answer: Insufficient mixing immediately after collection
If an EDTA tube is not mixed promptly and thoroughly after blood enters, the EDTA cannot chelate calcium effectively and micro-clots form, making the specimen unsuitable for CBC.
Specimens for cold agglutinins must be transported to the lab:
Answer: At 37°C to prevent premature cold agglutination
Cold agglutinin specimens must be kept at 37°C during transport because the antibodies react at lower temperatures, causing red cell clumping that would interfere with testing.
What is the correct centrifuge speed and time for most routine serum separation in a standard clinical laboratory?
Answer: 2,000–3,000 × g for 10 minutes
Most clinical laboratories centrifuge routine serum or plasma specimens at 2,000–3,000 × g for approximately 10 minutes to achieve complete separation without damaging cells.
When accessioning a specimen, which piece of information is MOST critical to verify first?
Answer: Patient identifiers matching the label and requisition
Patient identification — confirming that the label information matches the requisition — is the most critical step to prevent specimen mix-ups that could lead to dangerous misdiagnoses.
Which specimen type is MOST sensitive to temperature fluctuations and must be processed within 30 minutes without exception?
Answer: Ammonia (plasma)
Ammonia levels rise rapidly in unprocessed whole blood because red blood cells continuously produce ammonia; the specimen must be placed on ice and centrifuged within 15–30 minutes.