Specimen Handling and Processing Flashcards

At what temperature range should most routine chemistry specimens be stored if analysis is delayed?

Answer: Refrigerated (2-8 degrees C)

Most routine chemistry specimens should be refrigerated at 2-8 degrees C if testing is delayed, as this slows cellular metabolism and analyte degradation.

What is the pneumatic tube system used for in specimen transport?

Answer: To rapidly transport specimens from collection areas to the laboratory through pressurized tubes

Pneumatic tube systems use air pressure to rapidly transport specimen containers through a network of tubes between collection areas and the laboratory.

Why should blood specimens for coagulation testing NOT be collected from a heparin lock or heparinized line?

Answer: Residual heparin will falsely prolong coagulation test results

Even trace amounts of residual heparin from a line contaminate the specimen and falsely prolong PT and aPTT results, making coagulation testing unreliable.

What does the term 'preanalytical variable' refer to in specimen handling?

Answer: Any factor before analysis that can affect the accuracy of test results

Preanalytical variables are any factors occurring before laboratory analysis that can influence test results, including collection technique, transport, and processing.

A specimen is labeled as 'QNS' by the laboratory. What does this abbreviation mean?

Answer: Quantity Not Sufficient

QNS means 'Quantity Not Sufficient,' indicating that the specimen volume is inadequate to perform the requested test(s).

What is the proper procedure for mixing a blood specimen collected in an anticoagulant tube?

Answer: Gently invert the tube 8-10 times

Anticoagulant tubes should be gently inverted 8-10 times immediately after collection to ensure thorough mixing without causing hemolysis.