Keratinocyte Growth Supplement-animal component free (KGS-acf) is a medium supplement designed for the optimal growth of normal human keratinocytes in vitro. It is a sterile, concentrated (100X) solution which contains non-animal source of growth factors, hormones, and proteins necessary for the culture of normal human keratinocytes. The supplement is formulated (quantitatively and qualitatively) to provide an optimally balanced growth environment that maximally promotes the growth of normal human keratinocytes in vitro. The supplement is designed as an additive for keratinocyte medium-defined (KM-acf, Cat. No. 2121) and should be used in conjunction with that medium.