CLC CLC Specimen Collection, Handling & Pre-Analytical Processes

Question 1

The pre-analytical phase of laboratory testing is considered the most error-prone phase. Which of the following is a common pre-analytical error?

Accepted Answer

Hemolyzed specimen due to improper collection technique

Answer

Hemolysis from improper venipuncture technique is one of the most frequent pre-analytical errors, which can falsely alter results for multiple analytes.

Question 2

According to CLSI guidelines, what is the recommended order of draw when collecting multiple tubes during a single venipuncture?

Accepted Answer

Blood culture → citrate → SST → heparin → EDTA

Answer

CLSI GP41 specifies the order: blood cultures first, then citrate (blue), then SST or plain red, then heparin (green), then EDTA (lavender) to prevent cross-contamination between additives.

Question 3

A laboratory consultant reviews rejection criteria and notes that a urine specimen for culture arrived in the laboratory 4 hours after collection without refrigeration. What is the appropriate action?

Accepted Answer

Reject the specimen and request a new collection

Answer

Unrefrigerated urine held more than 2 hours before culture is typically rejected because bacterial overgrowth invalidates culture results.

Question 4

Which anticoagulant tube is the correct choice for a prothrombin time (PT/INR) test?

Accepted Answer

Sodium citrate (blue top)

Answer

Sodium citrate (blue top) tubes are required for coagulation studies including PT/INR because citrate preserves clotting factors by chelating calcium.

Question 5

A phlebotomist collects a citrate tube but it is only 80% full. What is the most significant concern with this specimen?

Accepted Answer

Altered blood-to-anticoagulant ratio affecting coagulation results

Answer

Citrate tubes require a precise 9:1 blood-to-anticoagulant ratio; underfilling alters this ratio and leads to falsely prolonged coagulation results.

(CLC) Certified Laboratory Consultant Practice Test

(CLC) Certified Laboratory Consultant Practice Test

CLC CLC Specimen Collection, Handling & Pre-Analytical Processes