When
3:30 – 4:30 p.m., March 6, 2025
Presenter:
Chad Borges, Associate Professor
Arizona State University
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Exposure of biospecimens to thawed conditions, which often exist well below 0 °C, can alter molecular components such that they no longer reflect in vivo reality—the purpose for which they were collected. This commonly happens without any indication of it having occurred, which can readily lead to irreproducible or even misleading results, particularly in ‘omics-type studies where it sets false discovery traps in which more molecular variation is produced from ex vivo artifacts than a biological phenomenon of interest.
This talk will provide an overview of two research projects that address these issues. The first project centers on development of analytically accessible endogenous markers of blood plasma and serum exposure to thawed conditions (> -30 °C). The first of these is a 10-microliter, dilute-and-shoot, intact-protein mass spectrometric assay of albumin proteoforms called ΔS-Cys-Albumin that, aided by a now-established rate law, quantifies cumulative exposure of archived plasma and serum samples to thawed conditions. The biochemical principles that underpin this marker are presently under development into plate reader assays for widespread accessibility in biomedical laboratories. The second project focuses on the creation and engineering of low-cost exogenous visual time-temperature indicators with unique color-changing autocatalytic reaction kinetics for tracking cumulative temperature exposures of any biospecimen above thresholds of -67 °C, -37 °C, -18 °C, or 0 °C at the individual aliquot level.
Hosted by: Dr. Michael Marty