I am doing a ChIP assay, I am checking my samples protein concentration with the bio rad protein assay. When i place my sample into my bio rad solution, the protein seems to clump together. I treated my cells with either DMSO or TCDD for 1.5H. Then I add 1% formaldehyde for ten mins. Then I washed with one Ice cold pbs. Next i peleted my cells and remove the extra pbs and store in -80. Then i attempted to do the bio rad protein assay and Thats where i got my problem.
on a side note my cells were grown in 100mm plates and at 100 confluency.
Any help would be greatful