I know mass spectrometry will work. But, is there any simple and straightforward method to distinguish between the two proteins of the same molecular weight? They are cryptochromes and photolyases. I have tried western blot with an antibody against Cryptochromes which cross-reacted with my other protein which is a photolyase and showed bands in both lanes. In the sample I suspect as cryptochrome it showed a single clean band. in the band I suspect as photolyase it showed multiple bands also with the correct band which looked smeary. Any help is appreciated.