ASPT Specimen Handling and Processing 2

Question 1

What is the maximum time a whole blood specimen should remain at room temperature before centrifugation if a serum specimen is needed?

Accepted Answer

2 hours

Answer

Most serum specimens should be centrifuged within 2 hours of collection to prevent cellular metabolism from altering analyte values.

Question 2

Which tube additive can cause falsely elevated potassium results if the specimen is hemolyzed?

Accepted Answer

EDTA

Answer

EDTA chelates calcium and can cause potassium to leak from red blood cells when hemolysis occurs, falsely elevating potassium levels.

Question 3

A specimen labeled 'STAT' arrives at the lab at the same time as a routine specimen. Which specimen should be processed first?

Accepted Answer

The STAT specimen, as it has higher priority

Answer

STAT specimens always take priority over routine specimens because they indicate urgent patient care needs.

Question 4

What is the purpose of inverting a blood collection tube after collection?

Accepted Answer

To mix the additive with blood

Answer

Gentle inversion mixes the tube additive (anticoagulant, gel separator, etc.) thoroughly with the blood specimen.

Question 5

Which specimen storage condition is required for cold agglutinin testing?

Accepted Answer

Keep warm at 37°C until testing

Answer

Cold agglutinin specimens must be kept warm (37°C) because cold temperatures cause the antibodies to bind and give false results.

(ASPT) American Society of Phlebotomy Technicians Practice Test