I am analyzing the autolysis of bovine trypsin and have run a gel with the trypsin samples varying in temperature and time. Trypsin is about 23 kiloDaltons and I can identify that band, but I have a band that shows up with just the trypsin and buffer, and also with the trypsin, buffer, and inhibitor (the inhibitor has a molecular weight of about 28 kD). the band is actually much darker in the inhibitor samples even though the concentration of trypsin protein is the same. The trypsin sample was given to me in a tris buffer (MW 121 kD) and I used a Phosphate buffered saline. Could the buffers I'm using affect the banding pattern?