Lonza's Human Mammary Epithelial Cells (HMEC) are isolated from adult female breast tissue. The cells have been primarily utilized to understand the formation of breast cancer. Cryopreserved Human Mammary Epithelial Cells are guaranteed through 15 population doublings, express cytokeratins 14 and 18 and are negative for cytokeratin 19.All cells test negative for mycoplasma, bacteria, yeast, and fungi. HIV-1, hepatitis B and hepatitis C are not detected for all donors and/or cell lots. A Certificate of Analysis is provided for each cell lot purchased.