Which of the following collection tubes contains thixotropic gel?

Question

Quizplus · Accepted Answer

The plasma separation tube (PST) contains thixotropic gel; the glass tubes have a green-gray (marbled) top, and the plastic tubes have a light green top. Thixotropic gel, a synthetic gel, has a density between that of red cells and plasma or serum; it settles between the two during centrifugation, forming a barrier that facilitates retrieval of the liquid portion without cellular contamination. Ethylenediamine tetraacetic acid (EDTA) is the anticoagulant found in the lavender-topped tube that prevents platelet clumping and preserves the appearance of blood cells for microscopic examination. The red plastic tube contains a silicone additive to activate clotting.

Which of the Following Collection Tubes Contains Thixotropic Gel