Empirically tracking the exposure of human plasma & serum samples to thawed conditions
Description
This presentation will described the concept, methodology, validation and performance characteristics of a 10-µL, dilute-and-shoot, intact-protein mass spectrometric assay of albumin proteoforms called “Delta-S-Cys-Albumin” that serves as an endogenous marker of P/S exposure to thawed conditions based on the inexorable ex vivo S-cysteinylation (oxidizability) of albumin. The multi-reaction chemical mechanism that drives changes in albumin S-cysteinylation is known and the rate law for it was established and accurately modeled in P/S—enabling back-calculation of the time at which unknown P/S specimens have been exposed to the equivalent of room temperature. Results from blind challenges and two unanticipated case studies that revealed unexpected integrity problems in sets of nominally pristine P/S samples will be presented.
United States
