This line was originally thought to be derived from an epidermal carcinoma of the mouth, but was subsequently found, based on isoenzyme analysis, HeLa marker chromosomes, and DNA fingerprinting, to have been established via HeLa cell contamination. The cells are positive for keratin by immunoperoxidase staining. KB cells have been reported to contain human papillomavirus 18 （HPV-18） sequences.
Propagation:
Complete growth medium: RPMI-1640+10%CS+P/S
Temperature: 37.0C
Atmosphere: air, 95%; carbon dioxide （CO2）, 5%
Subculturing:
Protocol: Remove medium, and rinse with 0.25% trypsin, 0.53mM EDTA solution. Remove the solution and add an additional 1 to 2 ml of trypsin-EDTA solution. Allow the flask to sit at room temperature （or at 37C） until the cells detach. Add fresh culture medium, aspirate and dispense into new culture flasks. Subc*tion ratio: A subc*tion ratio of 1:2 to 1:4 is recommended Medium renewal: 2 to 3 times per week
