100A260/ml RIPA buffer - what does thi mean? (May/28/2006 )
I found the following description in the material and methods of immunoprecipitation in an article:
" protein extracts were solubilized at 100 A260/ml RIPA buffer"
What does this mean?
Why not saying the amount of total protein (eg. 1mg total protein/ml buffer)?
Does this mean they don't quantitfy protein concentration of their lysates?
it would seem that they are saying that they use 1 ml ripa buffer for every 100 absorbance units at 260nm (could they have meant milliabsorbance units?).
since they are using 260nm it appears that they are determining the nucleotide concentration rather than the protein concentration (unless the have a protein with an absorbance maximum at or near 260nm). this makes it reasonable to use absorbance units (od units) to describe concentration.
I totally agree with you using the OD units (a260nm) for concentration is a bit odd!
But is published article, I might right to them asking what do they mean.