Three separate questions at receipt

Every specimen that reaches the bench has traveled through the same set of stages: collection, primary closure, transport under some temperature and time condition, receipt inspection, separation, and analysis. At each stage, something could go wrong in one of three independent ways, and receiving staff have to check all three before a result is released.

Biological stability asks whether the measurand itself is still what it was at the moment of collection. Cells in whole blood keep metabolizing after the needle comes out. Gas exchange can happen across an air bubble in a blood gas syringe. Light-sensitive analytes like bilirubin degrade under ambient light. None of this shows on the outside of the tube.

Physical integrity asks whether the specimen and its container arrived intact: closed, unbroken, correctly filled, without leakage, evaporation, or gross contamination. A federal quality-system requirement calls for the laboratory to define, monitor, and document the storage and handling conditions a specimen needs, and to follow the manufacturer's instructions when they exist.

Identification security asks whether the specimen in front of you is provably the one collected from that patient at that time. A perfectly chilled, perfectly sealed specimen with a mismatched or illegible label is not acceptable for release, no matter how well it traveled. These three checks are independent: passing one says nothing about the other two.

This is the reusable mental model for what follows: every risk described below is a variation on what can happen to biological stability, physical integrity, or identification security at one of these stages.

Ask stability, integrity, and identity as three separate questions, because a specimen can pass two and fail the third.