In some species minor cross reactions with some larger proteins are seen. These may contain related iron-sulfur binding motifs. Therefore size verification of the reacting band is required. Due to the small size of the protein, care should be taken to differentiate between chemiluminescent signal from PsaC and non-specific signals from chlotophylls or lipids if pigment is retained near the bottom of the blot.For the most optimal results use:thylakoid membranes or PSI particles,  solubilized in a SDS sample buffer (final concentrations: 63 mM Tris HCl, 10% glycerol, 2% SDS, 0.0025% bromophenol blue) with 2.5% beta-mercaptoethanol at 85C for 2 minutes. The samples were spun softly, then the supernatant loaded. This product can be sold containing ProClin if requested.