Certified Phlebotomy Technician Exam Specimen Handling and Processing 3

Question 1

A specimen for ammonia testing must be:

Accepted Answer

Placed on ice immediately and tested within 15–30 minutes

Answer

Ammonia specimens must be placed on ice immediately after collection and processed within 15–30 minutes because red blood cells continue to produce ammonia at room temperature.

Question 2

What is the primary reason for avoiding vigorous shaking of blood collection tubes?

Accepted Answer

It causes hemolysis by rupturing red blood cells

Answer

Vigorous shaking causes mechanical hemolysis by rupturing red blood cells, releasing intracellular contents that interfere with test results.

Question 3

Which specimen type is required for a prothrombin time (PT) test?

Accepted Answer

Plasma in a sodium citrate tube

Answer

PT testing requires plasma anticoagulated with sodium citrate (light blue-top tube) because sodium citrate chelates calcium to preserve coagulation factors.

Question 4

When aliquoting a specimen, which technique prevents cross-contamination between aliquots?

Accepted Answer

Changing pipette tips between each aliquot transfer

Answer

Changing pipette tips between each transfer prevents carryover and cross-contamination of specimens destined for different tests.

Question 5

A specimen for lactic acid testing should be transported:

Accepted Answer

On ice in a gray-top or lithium heparin tube

Answer

Lactic acid specimens must be placed on ice immediately and processed quickly because glycolysis by red blood cells will falsely elevate lactate levels.

Certified Phlebotomy Technician Exam Practice Test

Certified Phlebotomy Technician Exam Practice Test

Certified Phlebotomy Technician Exam Specimen Handling and Processing 3