I noticed that after staining cells with CMFDA, cell motion dramatically slowed and eventual stopped over time. At first I believed it was a environmental response – but then I found that this did not occur when using cells which had been transformed with GFP or with cells which were observed with transmitted light microscopy .
When I tried to dose the cells with anti-oxidants – such as Trolox (a vitamin E derivative) or Vitamin C – I found that the cells stayed motile for longer. The protective affect of the anti-oxidants only seemed to last for a short period of time. Other protectants, such as Oxyrase, may also aid – the key is probably a depletion of the oxygen, and hence free radicals, in solution. I presented this work at the American Society for Cell Biology Meeting (Dec 2005). My poster is available as a PDF here.