Intermittent Low recoveries for MAXPAR Conjugation
I have been successfully conjugating antibodies now for about 5 years with anywhere from 60-80% recovery and all of a sudden about 6 months ago I started experiencing intermittent low recoveries for antibodies within certain batches of conjugations. I typically conjugate around 4 antibodies at a time and 3 out of 4 will have good recovery and then one will have very low recovery, around 10% or less. This varied between suppliers of antibodies, and there seemed to be no pattern. I started checking the antibodies pre-conjugation with nanodrop to make sure that we were being sent the right amount of antibody from the companies and most of the time this has been true.
So in an effort to resolve this, I threw out all my old conjugation buffers, replaced the TCEP, switched to 30k spin columns to try to ensure better recovery, made sure my water bath was actually at 37 degrees C, and I performed a batch of conjugations today with the same, intermittent, random loss. One antibody recovered at around 60%, one at around 30% and one essentially nothing.
Wondering if anyone has any suggestions to troubleshoot what is going on????
Thanks,
Claude