Hela cells can be grown to the appropriate density usually 70% in a humidified chamber at 37°C, 5% CO2. HeLa cells in many labs are cultured in 75 cm2 flasks (or medium flasks). HeLa cells are grown in Dulbecco's Modified Eagle Medium with10% fetal bovine serum (FCS) and 1% MEM non-essential amino acids with penicillin-streptomycin at 1% is added to the culture media.
They can also be maintained in RPMI1640 containing penicillin-streptomycin, nonessential amino acids, sodium pyruvate, L-glutamine and 10% fetal calf serum and incubated in a humidified atmosphere with 5% CO2 at 37°C.