The Immortalized Mouse Wildtype M4+/+ Epidermal Keratinocyte Cells were derived from primary keratinocytes of newborn CD-1 mice. The primary keratinocytes were immortalized in subsequent cultures after passaging for an extended period. The immortalized cells display similar phenotype to the primary keratinocytes including the cobblestone-shape morphology. The Immortalized Mouse Wildtype M4+/+ Epidermal Keratinocyte Cells are non-tumorigenic. They also differentiate with increased calcium, maintain a relatively stable karyotype no more aberrant than cultured primary keratinocytes, and produce epidermis upon orthotopic grafting onto nude mouse hosts. Upon introduction of v-rasHa oncogene, the Immortalized Mouse Wildtype M4+/+ Epidermal Keratinocyte Cells produce squamous cell carcinoma in orthotopic skin grafts. These cells are useful in studies in epidermal keratinocyte biology and pathology.Immortalization Method: Immortalization in subsequent culturesBioSafety Level: IISpecies: MouseSource Organ: SkinGrowth Properties: AdherentMorphology: Cobble-stonePopulation Doubling: N/ASeeding Density: Thaw entire contents into an appropriate T25 flask as specified in the Propagation instructions.Markers: Keratin 14, Keratin 6Donor Age: N/ADonor Gender: N/ADonor Ethnicity: N/APropagation: The base medium for this cell line is Prigrow XI medium available at abm, Cat. No. TM011. To make the complete growth medium, add the following components to the base medium: 8% chelexed fetal bovine serum (TM999)*, Penicillin/Streptomycin Solution (G255) to a final concentration of 1% and 5 ng/ml recombinant human FGF7 (Z100595). Carbon dioxide (CO2): 5%, Temperature: +37.0°C.* abm does not recommend to use heat-inactivated FBS for cell culture unless specified otherwise.Quality Control: Immunofluorescence analysis of Keratin markersShipping Condition: Dry IceStorage Condition: liquid nitrogen or -180°C