Specimen Handling and Processing Flashcards
7 cards from real Certified Phlebotomy Technician Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Specimen Handling and Processing flashcards as text
A specimen for ammonia testing must be:
Answer: Placed on ice immediately and tested within 15–30 minutes
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.
What is the primary reason for avoiding vigorous shaking of blood collection tubes?
Answer: It causes hemolysis by rupturing red blood cells
Vigorous shaking causes mechanical hemolysis by rupturing red blood cells, releasing intracellular contents that interfere with test results.
Which specimen type is required for a prothrombin time (PT) test?
Answer: Plasma in a sodium citrate tube
PT testing requires plasma anticoagulated with sodium citrate (light blue-top tube) because sodium citrate chelates calcium to preserve coagulation factors.
When aliquoting a specimen, which technique prevents cross-contamination between aliquots?
Answer: Changing pipette tips between each aliquot transfer
Changing pipette tips between each transfer prevents carryover and cross-contamination of specimens destined for different tests.
A specimen for lactic acid testing should be transported:
Answer: On ice in a gray-top or lithium heparin tube
Lactic acid specimens must be placed on ice immediately and processed quickly because glycolysis by red blood cells will falsely elevate lactate levels.
What does the term 'hemolysis' refer to in the context of specimen quality?
Answer: Rupture of red blood cells releasing hemoglobin into plasma/serum
Hemolysis refers to the rupture of red blood cells, releasing hemoglobin and intracellular contents (potassium, LDH, AST) that interfere with many laboratory tests.
For a 24-hour urine collection, what instruction must the patient follow at the start of the collection period?
Answer: Discard the first morning void, then collect all subsequent urine
The patient discards the first morning void to establish a clean start time, then collects all urine for the next 24 hours including the final void.