Routine Blood CollectionsDifficulty 4/5
CLSI states that only certain tubes may be collected before the coagulation tube. Which describes them?
- AAny tube at all, provided the coagulation tube is filled completely to its stated volume
- BBlood culture tubes, glass nonadditive serum tubes, or plastic serum tubes without clot activator
- CBlood culture tubes, heparin tubes with gel, or plastic serum tubes containing a clot activator
- DEDTA tubes with gel separator, glass nonadditive serum tubes, or any gray closure tube
Show answer and rationale
Correct: B. This is the exception CLSI spells out explicitly, and it is exactly what a colour-list recitation misses. A clot activator is the disqualifier: a plastic serum tube may precede the coagulation tube only if it has none.
- C — A clot activator is precisely what disqualifies a serum tube from preceding the coagulation tube.
- D — EDTA binds calcium and would corrupt a coagulation result; it never precedes the citrate tube.
- A — Full filling matters for the citrate ratio but does not override the carryover rule.