Aplha, transcription related growth factors and stimulating factors or repressing nuclear factors are complex subunits of proteins involved in cell differentiation. Complex subunit associated factors are involved in hybridoma growth, Eosinohils, eritroid proliferation and derived from promotor binding stimulating subunits on the DNA binding complex. NFKB 105 subunit for example is a polypetide gene enhancer of genes in B cells.Azide Free Serum for cell culture FBS fetal bovine serum. Filtered serum for sterility. The polyclonal serum contains no red or white blood cells or clotting factors; it is the blood plasma not including the fibrinogens. Serum includes all proteins and antibodies not used in blood clotting (coagulation) and all the electrolytes, antibodies, antigens, hormones, and any exogenous substances like drugs and microorganisms. Plasmas on request.