Vacutainer tubes may contain additives designed to stabilize and preserve the specimen prior to analytical testing.
When a tube is centrifuged, the materials within are separated by density, with the blood cells sinking to the bottom and the plasma or serum accumulating at the top.
Tubes containing gel can be easily handled and transported after centrifugation without the blood cells and serum mixing.
[7] ("light blue") (weak calcium chelator/anticoagulant) Plasma separator gel ("navy") Fluoride Oxalate Grey, Green, Yellow, Purple 1.
Purple (mitogen) tube Vacutainer technology was developed in 1947 by Joseph Kleiner,[2] and is currently marketed by Becton Dickinson (B-D).
The plastic tube version, known as Vacutainer PLUS, was developed at B-D in the early 1990s by E. Vogler, D. Montgomery and G. Harper amongst others of the Surface Science Group as US patents 5344611, 5326535, 5320812, 5257633 and 5246666.
Vacutainers have the advantage of being prepared with additives, allowing easy multi-tube draws, and having a lower chance of hemolysis.