Fetal bovine serum specific cell type. When changing from batch to batch it is usual to adapt the cells to the new batch of material, for example, by mixing 50% of the old serum with 50% of the new serum and allowing the cells to acclimatise to the new material. Serum is stored frozen to preserve the stability of components such as growth factors. When serum is thawed, some precipitation may be seen. This is a normal phenomenon and it does not compromise the quality of serum in any way. The precipitate may be removed by transferring the serum to sterile tubes and
Blood plasma Blood plasma Blood plasma is a yellowish coloured liquid component of blood that normally holds the blood cells in whole blood in suspension; this makes plasma the extracellular matrix of blood cells. It makes up about 55% of the body's total blood volume. It is the intravascular fluid part of extracellular fluid (all body fluid outside cells). It is mostly water (up to 95% by volume), and contains dissolved proteins (6–8%) (i.e.—serum albumins, globulins, and fibrinogen), glucose, clotting factors, electrolytes (Na, Ca, Mg, HCO, Cl, etc.), hormones, carbon dioxide (plasma being the main medium for excretory product transportation) and oxygen.