how to settle the FBS contamination - (Nov/24/2008 )
Then you can filter it with a 0.22uM filter.
Maybe you are right in a way.
However i don't agree to do that, i don't know how much nutrient will lose after doing that.
And if it can be used to culture cells still leave to be tested.
Please note that ALL the companies that manufacture serum FILTER IT AT 0.1uM..........a 0.22uM filter is a sterilising filter and WILL NOT retain any growth factors from the serum. The only thing to mention is that the filter will get clogged with precipitate very quickly....so a standard 500ml 0.22uM filter will only allow you to filter about 100ml total.
So leave your serum in the split tubes to thaw....then filter it through a 0.22uM filter and then re-aliquot...... again only putting in 45ml into each flask.
p.s. please remember that most media's require a 10% serum concentration.....this means 55mls of serum to a standard 500ml of RPMI/DMEM.
Hope this is useful
Thanks very much for your advise.
Things happen as what you said, " the filter will get clogged with precipitate very quickly....
so a standard 500ml 0.22uM filter will only allow you to filter about 100ml total."
And i found it that if i add 10% of that FBS into DMEM, things turn out much easy. The liquid get thourgh the 0.22uM filter much much quickly. When i add the serum to 20%, it soon block the membran. So i try to filter every 500mL medium within that 55mL FBS before use. I think maybe it's the only method left, for not throwing them away.