Certified Phlebotomy Technician Specimen Handling and Processing Questions and Answers

Question 1

A phlebotomist is preparing to collect a blood specimen for an ammonia level. Which of the following handling procedures is critical for ensuring the accuracy of the test result?

Accepted Answer

The specimen must be placed in an ice slurry immediately after collection.

Answer

Ammonia levels in a blood specimen increase rapidly at room temperature. Chilling the specimen immediately in an ice slurry slows down the metabolic processes that lead to this increase, ensuring an accurate measurement.

Question 2

Which of the following analytes requires the blood collection tube to be protected from light as soon as it is drawn?

Accepted Answer

Bilirubin

Answer

Bilirubin is a light-sensitive analyte. Exposure to light, especially direct sunlight or fluorescent light, can cause it to break down, leading to falsely low test results. Therefore, the tube must be protected, often by wrapping it in aluminum foil or using an amber-colored tube.

Question 3

A phlebotomist receives an order to draw blood for a cold agglutinin test. What is the correct handling procedure for this specimen immediately following collection?

Accepted Answer

Place the tube in a 37°C heat block or incubator.

Answer

Cold agglutinins are antibodies that cause red blood cells to clump together at temperatures below body temperature. To prevent this from happening, which would interfere with the test, the specimen must be kept warm (at 37°C) until the serum can be separated from the cells.

Question 4

According to CLSI guidelines, what is the maximum amount of time that should elapse between the collection of a routine blood specimen for serum testing and the separation of serum from the cells by centrifugation?

Accepted Answer

2 hours

Answer

For most routine chemistry tests, serum or plasma should be separated from the cells within two hours of collection to prevent metabolic changes in the cells from altering the composition of the serum/plasma, which can lead to inaccurate results.

Question 5

A laboratory rejects a light blue top tube for a coagulation test. Which of the following is the most likely reason for specimen rejection?

Accepted Answer

The tube was only filled to 75% capacity.

Answer

Coagulation testing requires a specific ratio of blood to anticoagulant (9:1). An underfilled tube (short draw) will have an incorrect ratio, with too much anticoagulant, which will lead to inaccurate and prolonged clotting times. Most tubes have an indicator mark and must be filled to ±10% of that volume.

Certified Phlebotomy Technician Exam Practice Test

Certified Phlebotomy Technician Exam Practice Test

Certified Phlebotomy Technician Specimen Handling and Processing Questions and Answers