Hello,

Could you please give examples, like showing articles where passage number 190 is mentioned ? Because this looks like a very high number of passages, and I never heard about it, so I am very curious now to understand your question.

Best,

Yes mutations can accumulate during passages, but this passage number 190 specifically... I think it's misunderstanding

Moreover, I think that in the article that analyzed genomic integrity of PSCs after a highly extensive time in culture, the maximum number of passages they studied is number 161 (nearly 2 years of culture...already a tremendous work)

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0118307

Hello Praveen,

There is accumulation of chromosomal aberrations at higher passage. and at very low passages like 0-2, cells are not much specialised and haven't acquired surface markers properly. SO generally, the recommended passage number for pluripotent cells is from 3-10th. Generally we perform all experiments like characterization, differentiation etc.  during these passage no. As this is a safe range and cells don't compromise their chromosomal integrity upto these passages. But in case of some stem cells you can extend upto 15th passage no. So as a thumb rule, you can use your cells for characterization as long as they don't accumulate chromosomal abberrations (for higher passage you can confirm through karyotyping, if chromosomes are OK that is a practical validation and you can proceed with your experiments). Ideally if you don't do a karyotyping, then perform all experiments from passage no. 3-10.

Hope it helps !

Dear Clara, Jorg and Ajay,

thank you very much for the valuable inputs.

Best regards,

Praveen.