Phlebotomy Test Specimen Processing and Handling 2

Question 1

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

Accepted Answer

60 minutes

Answer

Whole blood specimens should be centrifuged within 60 minutes of collection to prevent cellular metabolism from altering analyte levels.

Question 2

Which additive tube must NEVER be inverted after collection?

Accepted Answer

None — all tubes require inversion

Answer

All additive tubes require gentle inversion immediately after collection to mix the additive thoroughly with the blood.

Question 3

A serum specimen appears hemolyzed. Which analyte result is MOST likely to be falsely elevated?

Accepted Answer

Potassium

Answer

Potassium is highly concentrated inside red blood cells, so hemolysis releases it into the serum, causing falsely elevated potassium values.

Question 4

When processing a urine culture specimen, the preferred storage condition before transport is:

Accepted Answer

Refrigeration at 2–8°C up to 24 hours

Answer

Urine for culture should be refrigerated at 2–8°C if not processed within 30 minutes to prevent bacterial overgrowth that would skew colony counts.

Question 5

What does 'aliquoting' a specimen mean in the laboratory context?

Accepted Answer

Dividing the specimen into smaller portions for separate tests or storage

Answer

Aliquoting is the process of dividing a primary specimen into smaller sub-samples so multiple departments can test the same collection without re-drawing the patient.

Phlebotomy Practice Test

Phlebotomy Practice Test

Phlebotomy Test Specimen Processing and Handling 2