We have been seeing a lot of variation in plasma samples we have been analyzing. I think it's due to sample handling. Does anyone have a nice SOP on how to optimally collect and handle plasma for MS based proteomics? The hard part is we work on plasma from all sorts of weird species

Imo "optimal" isn't as important as plain consistency. Just have them pick a tube/method and stick with it, and then assume random hemolysis, and be sure on your end you are thawing and aliquoting the same way, always fearful of "the blob". (👀 @mattwfoster.bsky.social)