Dear colleagues,

We observe suppression of mitochondrial activity (via MTT test) in a human glioblastoma immortalized cell line after exposure to a non-pharmacological (rather, physical) experimental factor. It seems that this suppression increases with the increase of the passage number (so, it looks like the effect of the given factor becomes stronger in "older" cells). We still work in the reasonable range (the first 2 tens of passages). What could be the mechanism or bias behind this? Thank you very much.