Specimen Handling and Processing Flashcards

A urine specimen for culture must be transported to the lab but will take 45 minutes. What is the correct action?

Answer: Refrigerate the specimen during transport

Urine culture specimens must be refrigerated if transport time exceeds 30 minutes to prevent bacterial overgrowth that would alter results.

Which of the following analytes requires a light-protected specimen container during transport?

Answer: Bilirubin

Bilirubin is photosensitive and degrades when exposed to light, requiring amber or foil-wrapped tubes during collection and transport.

What is the correct centrifugation speed range for most routine blood specimens?

Answer: 1,500–2,500 × g

Most routine blood specimens are centrifuged at 1,500–2,500 × g for 10–15 minutes to adequately separate cellular components from plasma or serum.

A plasma specimen is needed for STAT glucose testing. Which tube should be used?

Answer: Green top (heparin)

Lithium heparin (green top) tubes provide plasma immediately after centrifugation without a clotting wait time, making them ideal for STAT testing.

Which condition would cause a specimen to be rejected by the laboratory?

Answer: Specimen with clots in an EDTA tube

Clots in an EDTA tube indicate improper mixing and will interfere with cell counts and other hematology tests, requiring specimen rejection.

What is the purpose of a blood culture bottle's aerobic and anaerobic pairing?

Answer: To detect both oxygen-requiring and oxygen-sensitive organisms

Aerobic bottles support oxygen-requiring bacteria while anaerobic bottles support organisms that are inhibited or killed by oxygen, providing complete pathogen detection.

How should a specimen be handled if it cannot be tested within the recommended stability window?

Answer: Discard and recollect if possible

When a specimen exceeds stability limits, the preferred action is recollection because testing an unstable specimen produces unreliable results that could harm patient care.