After selection cells are usually maintained in a reduced concentration of the antibiotic. Although I would not have the antibiotic present in the media during experiments.

After selection cells are usually maintained in a reduced concentration of the antibiotic. Although I would not have the antibiotic present in the media during experiments.

I agree with Richard's response and would like to add that cultures that are to be maintained for future research need to be maintained roughly at half of the selection concentration of the drug/antibiotic that was used for selection. For experimental purpose, one needs to maintain cultures for at least one population doubling (about a day for most cell types) without any antibiotic and the medium needs to be changed before any experiment.

If you have stable transduced cells you can think about culturing the without antibiotics and just "select" them again after several passages. But to be on the safe side I would keep the antibiotics. For an experimental setup it is advisable to remove antibiotics because of their often translation or transcription influencing action

Regards

sven