Q = Are these sterile?
A = Our standard plastic petri dish range, PER-150-100 etc. have been manufactured and packed in aseptic conditions but have not been irradiated. So, essentially they are sterile but not to the guaranteed high level of sterility which irradiated plates are.
We do also offer a range which has been sterilised by irradiation - PER-170-100 etc.
We do sell large numbers of each range, so I think customers probably use both types for growing cultures, but if it’s vital that they are completely sterile you should use the PER-170 range. There is of course a difference in price.