Biosafety classification is based on U.S. Public Health Service Guidelines, it is the responsibility of the customer to ensure that their facilities comply with biosafety regulations for their own country.
Overexpression of CDK4 and hTERT in neonatal foreskin keratinocyte induced a dramatic upregulation of p16INK4a and milder upregualtion of p53 and p21WAF1, which became unresponsive to UV irradiation. Despite the high levels of these checkpoint factors, Ker-CT cells divide in an apparently normal regulated fashion, are able to respond to changes in calcium levels, retain the stem cell phenotype, and fully differentiate and stratify in organotypic culture Ref
Ramirez R, et al. Bypass of telomere-dependent replicative senescence (M1) upon overexpression of Cdk4 in normal human epithelial cells. Oncogene 22(3): 433-44, 2003. PubMed: 12545164

Ramirez R, et al. Bypass of telomere-dependent replicative senescence (M1) upon overexpression of Cdk4 in normal human epithelial cells. Oncogene 22(3): 433-44, 2003. PubMed: 12545164 As the cells become more confluent, increase the volume of media as follows: under 25% confluence feed cells 5 mL per 25 cm2, 25-45% confluence then feed cells 7.5 mL per 25 cm2, over 45% confluence then feed cells 10 mL per 25 cm2.
Ramirez R, et al. Bypass of telomere-dependent replicative senescence (M1) upon overexpression of Cdk4 in normal human epithelial cells. Oncogene 22(3): 433-44, 2003. PubMed: 12545164
Vaughan M, et al. H-ras expression in immortalized keratinocytes produces an invasive epithelium in cultured skin equivalents. PLoS One 4(11): e7908, 2009. PubMed: 19936293
