Human Dermal Epidermal Keratinocytes from Creative Bioarray are isolated from normal human skin tissue. Human Dermal Epidermal Keratinocytes are grown in T25 tissue culture flasks pre-coated with gelatin-based coating solution for 2 min and incubated in Creative Bioarray�s Culture Complete Growth Medium generally for 3-7 days. Cultures are then expanded. Prior to shipping, cells at passage 3 are detached from flasks and immediately cryo-preserved in vials. Each vial contains at least 0.5x10^6 cells per ml. The method we use to isolate epidermal keratinocytes was developed based on a combination of established and our proprietary methods. Cells can be expanded for 3-7 passages at a split ratio of 1:2 or 1:3 under the cell culture conditions specified by Creative Bioarray. Repeated freezing and thawing of cells is not recommended.