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.
Best Answer: Those spinning devices are called centrifuges, and they are used to separate the blood into its component parts so that tests can be performed on that component alone. The denser materials (like red blood cells) sink to the bottom, while the lighter ones (like plasma) float to the top.