Absolute zero is the coldest possible temperature, at which no heat is left in a substance and its particles display no motion whatsoever. Absolute zero is equal to 0 K on the Kelvin scale, which is... Absolute zero is the coldest possible temperature, at which no heat is left in a substance and its particles display no motion whatsoever.
Serum is plasma that has been allowed to clot. It is prepared in the same way as plasma; however, the blood is collected into a tube with no anticoagulant. While spinning in the centrifuge, the clot moves with the cells to the bottom of the blood collection tube, leaving the serum on top.
Blood plasma is separated from the blood by spinning a tube of fresh blood containing an anticoagulant in a centrifuge until the blood cells fall to the bottom of the tube. The blood plasma is then poured or drawn off. Blood plasma has a density of approximately 1025 kg/m3, or 1.025 g/ml. Blood serum is blood plasma without clotting factors. Plasmapheresis is a medical therapy that involves blood plasma extraction, treatment, and reintegration.