Can i still use freezing medium if i used PES filter to filter my DMSO? - (Aug/02/2012 )

hi guys.

FYI, i was preparing my freezing medium using FBS plus 10% of DMSO. I sterile-filtered my DMSO via PES membrane filter straight into my FBS and to my surprise, the PES membrane material was dissolved in DMSO... As so, i assume that the freezing medium i prepared earlier on contains not only FBS and DMSO, but also the PES membrane...

In this case, can i still use the freezing medium, after some kind of re-filtering, etc? Or should i just discard the whole bottle of freezing medium?

Thanks...

I wouldn't risk using it. Even if your cells survive being frozen in it and then thawed, you will have no idea of the potential effect of the membrane components on the behaviour of your cells for future work.