Passaging HEK293 cells - adding antibiotics (Apr/24/2011 )
Im a new student, learning cell culture. I am wondering whether you need to add antibiotics every time you passage HEK293 cells? or only after freeze thawing them?
It depends on the SOP in your lab. In general, there are two sides: you should always add antibiotic, because it's very difficult to avoid contamination without them.
On the other hand, people using antibiotics all the time tend to get sloppy and careless with their cells. Also, if the antibiotic is always present in the medium it may slow down a growing contamination. When that happens, you will not be able to see the contamination, but your cells will suffer from it nevertheless: a change in growth rate, physiology and gene expression will occur.
So, the final decision is always up to your supervisor.
All the best,