Mesenchymal Stem Cell Growth Supplement serum free (MSCGS-sf) is a medium supplement designed for the optimal growth of human primary mesenchymal stem cells (MSCs) in vitro. It is a sterile, concentrated (100X) solution which contains growth factors, hormones, and proteins necessary for the culture of normal human MSCs. The supplement is formulated (quantitatively and qualitatively) to provide a defined and optimally balanced serum free growth environment that maximally promotes the growth of human primary MSCs in vitro. The supplement is designed as an additive for mesenchymal stem cell serum free medium (MSCM-sf, Cat. No. 7511) and should be used in conjunction with that medium.