Re: [ccp4bb]: Filters for DLS measurements

[Richard Gillilan <reg8@cornell.edu>]

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> 
> Which filter size do you normally use to prepare protein solutions for
> dynamic light scattering measurements? Is it really necessary to take 0.02
> micrometer filters as recommended by ProteinSolutions and found in many
> papers, or are 0.2 or 0.1 micrometer filters also reliable?
> 

I've found the smaller size filters (0.02) more difficult to use
reliably. They seem to break or leak easily under modest pressure.
In some cases, however, they seem to be necessary. I always try
a larger filter first. With some practice you can recover most
of the protein only slightly diluted and filter again with 
a finer mesh if need be.

 Richard Gillilan
 MacCHESS
 Cornell University