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.
Serum iron is measured in micrograms of iron per deciliter of blood (mcg/dL). Transferrin is a protein in the blood that transports iron throughout your body. Examining how much iron is in the transferrin proteins can tell your doctor if you have too much or too little iron in your blood.