I have revived a vial of CHO PA DUKX parental cell line but it took 2 months to recover and then started growing fine. Now I suspect that the cells which I am growing are the not the original ones (because they recovered very tough and I think that there might be some genetic alterations in the cells). I want to confirm that they are from the CHO PA DUKX cell line only (the original without any mutations). So can anyone please suggest the type of test and protocol to perform to confirm this?