Human Corneal Growth Supplement (HCGS) is a sterile, concentrated (100×) solution intended for use with EpiLife® medium to culture human corneal epithelial cells. HCGS is an ionically-balanced supplement containing all of the growth factors, hormones, and tissue extracts necessary for the culture of human corneal epithelial cells, and is provided in the correct amount to supplement a 500 ml bottle of medium.