Subject: How long do I centrifuge serum to remove denatured proteins?

I am trying to find out what happens to the proteins in the bovine serum we 
use as a lubricant in testing hip implants.  I am taking samples of the serum 
at various time intervals and I'm testing it for protein content with 
capillary electrophoresis and with SDS-Page and Western Blot.  I need to 
remove any denatured proteins to analyse what is left. Because they tend to 
precipitate, I think centrifuging the samples will remove the denatured 
proteins, but I have no idea how long I should centrifuge so I can get them 
all but not cause more denaturing to occur. 

Re: How long do I centrifuge serum to remove denatured proteins?