We are having some issues with the MAGEA1 protein delivered recently (CSB-EP013323HU). We have tested it on WB using a panel of antibodies and immune sera and did not see any band at the expected molecular weight. There is a slight band visible when using an anti-His antibody, however, it does not correspond to the width/intensity of the Ponceau-stained band (Ponceau being much less sensitive than WB). In MS MAGEA1 peptides could be detected, however, a multitude of other unrelated peptides were identified as well. I am wondering if the protein Cusabio have purified really is MAGEA1. The first time the protein did not pass your internal QC which points to some issues with it.
Could you please confirm how you QC your proteins? Is it done only by Coomassie stain or is WB applied too? Also, please check your lot again for MAGEA1 and its concentration (not whole protein concentration). For our application it is very important that we use pure protein and the lot which was sent recently does not seem to be suitable