Challenge Your Exam Readiness With Our Free Phlebotomy Practice Questions

Syringe draws can be useful for fragile, collapsing veins because you control initial suction. However, once blood is obtained, it must be transferred safely to additive tubes using a closed, manufacturer-approved safety transfer device. The correct technique (Option C) is to seat each tube on the transfer device and allow the tube’s vacuum to draw blood in—without depressing the syringe plunger. This preserves the correct additive-to-blood ratio, limits hemolysis and aerosol formation, and maintains a closed system that protects the phlebotomist. Injecting through the stopper with the syringe needle (Option A) creates positive pressure that can hemolyze cells, cause backflow/aerosols, and damage the stopper. Pouring (Option B) is an open transfer that risks contamination, biohazard exposure, and incorrect volumes. Letting blood sit to “settle” (Option D) delays mixing with additives, promotes clot formation where not intended, and increases preanalytical error. After each tube fills, gently invert the labeled tube the specified number of times to mix additives evenly, then promptly deliver for processing.