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
A specimen is received with two different patient names on the label and the requisition. The phlebotomist should:
Answer: Reject the specimen and request a recollection with correct labeling
Mismatched patient identifiers constitute a labeling error; the specimen must be rejected and recollected to prevent potential misidentification and patient harm.
Light-sensitive specimens such as bilirubin or vitamin B12 should be:
Answer: Wrapped in foil or placed in amber containers to block light exposure
Bilirubin and certain vitamins degrade rapidly when exposed to fluorescent or UV light, so wrapping tubes in aluminum foil or using amber containers preserves analyte stability.
When reconstituting a lyophilized (freeze-dried) control or reagent, which technique ensures the most accurate result?
Answer: Gently swirl and roll the vial until fully dissolved without introducing bubbles
Gentle swirling prevents foaming and bubble formation that can trap undissolved material, ensuring complete reconstitution and accurate analyte concentrations.
A phlebotomist notices a centrifuged SST tube has a very thin serum layer. This is MOST consistent with:
Answer: Polycythemia (elevated hematocrit)
Polycythemia results in a higher proportion of red blood cells relative to plasma, producing a thin serum layer after centrifugation of a clotted specimen.
Which of the following is NOT an acceptable reason to reject a specimen in the laboratory?
Answer: Specimen collected 45 minutes before transport for routine chemistry
A 45-minute pre-transport interval for routine chemistry is within acceptable limits and does not constitute grounds for rejection, unlike underfilled coagulation tubes, hemolysis for potassium, or expired tubes.
What is the primary reason sodium fluoride (gray-top) tubes are used for glucose testing?
Answer: Sodium fluoride inhibits glycolysis, preventing cells from consuming glucose
Sodium fluoride is a glycolytic inhibitor that blocks red blood cell glycolysis, preventing the breakdown of glucose and preserving the specimen's glucose concentration for up to 24 hours.
After centrifugation, a serum specimen should ideally be transferred off the clot within:
Answer: 2 hours
Serum should be transferred to a secondary aliquot tube within 2 hours of centrifugation; prolonged contact with the clot allows metabolic processes and cellular release to alter analyte concentrations.