Freezing DMSO - (Feb/27/2013 )

Is it ok to freeze 1%DMSO and 0.01%DMSO for future use in MTS assay as drug carrier? I know people it at 10% not sure if lower concentration makes a difference.

1% or less will not prevent the formation of ice crystals, which is what kills the cells. MTS and MTT assays rely on active mitochondria to work - you need your cells to be alive.