CLC Specimen Collection, Handling & Pre-Analytical Processes Flashcards
6 cards from real CLC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CLC Specimen Collection, Handling & Pre-Analytical Processes flashcards as text
A laboratory consultant reviews specimen transport policies. For most routine chemistry tests, specimens should be centrifuged and separated within how many hours of collection?
Answer: Within 2 hours
Most routine chemistry specimens should be centrifuged and the serum or plasma separated from cells within 2 hours of collection to prevent analyte degradation or cellular exchange.
Which specimen is the gold standard for diagnosing a venous thromboembolism (VTE) using D-dimer testing?
Answer: Citrate plasma (blue top tube)
D-dimer is measured in citrate plasma (blue top tube), consistent with other coagulation markers, though some assays are validated on other plasma types.
A phlebotomist must collect a specimen from a patient with a peripherally inserted central catheter (PICC). What is the recommended practice before drawing the specimen?
Answer: Discard the initial 5–10 mL (or per policy) before collecting the specimen
When drawing from a PICC or central line, the first 5–10 mL of blood (or the volume specified by policy) should be discarded to remove flush solution and potential contaminants before collecting the specimen.
Which practice violates proper specimen integrity during transport to a reference laboratory?
Answer: Shipping specimens at ambient temperature when cold chain is required
Shipping temperature-sensitive specimens (such as those requiring refrigeration or freezing) at ambient temperature violates cold chain requirements and can cause analyte degradation.
A laboratory consultant evaluates specimen rejection data and finds that 15% of STAT specimens are being rejected for mislabeling. Which quality improvement tool is most appropriate as the first step?
Answer: Conduct a root cause analysis (RCA) to identify where labeling errors originate
Root cause analysis (RCA) is the appropriate first step to systematically identify the underlying causes of the labeling errors before implementing targeted solutions.
Which factor is a recognized pre-analytical variable that can interfere with serum testosterone immunoassay results?
Answer: Time of day of specimen collection
Testosterone levels follow a diurnal rhythm and are highest in the morning; CLSI and most reference labs specify early morning collection (7–10 AM) for accurate testosterone measurement.