Preparing BSA standards - (Nov/04/2010 )

Hi all,

I am preparing BSA standards, and when I do the standard curve, for the y=mx+c, my m is around 0.07. Whereas in a different batch of BSA (frozen aliquots), it is around 0.007. Why is there a 10 fold difference? The m value is always consistent and no problem with R sq value.

Thanks.

What protein detection system are you using (e.g. BCA, Bradford, Lowry, spectrophotometry)?

are you sure the frozen standards are the same concentration as the standard you made fresh?

did you notice any sediment in the defrosted bsa?

did you mix the frozen bsa after defrosting?