Dear All I am purifying a protein from liver. In first step I spotted protein in Flow Through and could see intense band in SDS PAGE. I pooled the fraction and did second column. Surprisingly I could not see UV absorbance or even any band in the SDS. I used PMSF as protease inhibitor from begining of purification. First column I used Tris buffer (pH 8) and for second column I used MOPS buffer (pH 6).
What could be the reason? Thanks in advance Sajid