I used it with rituximab antibody to develop a depletion assay. I was able to spike couple it to beads and it worked perfectly. The specificity was as expected! I was also able to use it through ELISA to measure the level of depletion. On a more technical note, the product was super easy to resuspend (which is not always the case with lyophilized products). It's also been very stable at 4C after resuspension.