Will lyophilisation kill all bacteria?

Rafael Maldonado not-this at not-this.com
Fri Jul 25 04:25:43 EST 2003

Just to let you know: in the market there are some filters said to be 
non-adherent to proteins. But we have suffered some special sticky 
proteins which can be lost in any place, even in the wall of the tubes. 
So my advice is to filter a small part of the sample, and after that you 
may wash the filter in sample buffer (probably you have to break the 
plastic containgin the filter) to check how much of your protein was in 
the filter. Usually, less than 10% is OK. With some proteins, we lost 
more than 90%...


Tom Anderson wrote:
> On 23 Jul 2003, Wolfgang Schechinger wrote:
>>Will flushing the filter with BSA, gelatin, skim milk or whatever
>>minimize the adhesion of target protein to the membrane?
> smart idea. however, may i suggest not using skimmed milk? it has rather
> large (several microns across!) lumps in it which will block the filter.
> of course, you could always filter the milk to clear the lumps (i've
> successfully used a 0.45 um and a 0.2 um syringe filter in series to do
> this, as a 0.2 on its own clogs way too fast; it also helps to centrifuge
> the milk first to get rid of really huge bits), then use that to block a
> filter, then filter the protein with that.
> alternatively, i have heard of FCS being used for blocking. however,
> that's (a) expensive and (b) likely to contaminate the protein solution.
> on the gripping hand, these filters are designed for minimum protein
> binding, so none of this should be necessary.
> tom

Rafael Maldonado, Ph. D.
Division of Genetics
University of Alicante

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