Hi everyone! I performed two chemical cross-linkings with my peptide using glutaraldehyde and BS3, as cross-linkers. After that, I stained the gels with the silver staining kit (Invitrogen). In both gels, I can see an uneven line around 15 KDa. I assume it is an artefact of the staining process, but I would like to be sure. Any ideas? Thanks in advance, Enea