Setup, so nobody has to ask: WXT · KP · New Zealand.
I suspect the honest answer is that it depends, in which case I would like to know on what.
Assume I can obtain either option without difficulty, so availability is not the deciding factor.
Is there a defensible reason to prefer one, or is this a coin flip?
Aggregated, published test results and vendor ratings built from submitted batches. Methodology stated, dataset browsable, no listing fees.
Browse resultsAsk PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.