An Aptamer‐Based Approach to Assess the Human Plasma Proteome for Pre‐Analytical Variability

Abstract

The quality of clinical samples is of utmost importance when conducting biomedical research with OMICS‐based assays as the variability introduced before sample analysis is a potential confounder in the results. In this study, we used the aptamer‐based SOMAscan® proteomic technology to characterize pre‐analytical variability in human EDTA plasma. The goal of the study was to investigate how variation in the pre‐analytical steps during processing of whole blood to plasma impacts the plasma proteome. Whole blood was obtained from apparently healthy individuals and was collected in a randomized sequence of six EDTA tubes. The pre‐analytical variables included prolongation of the processing start time, storage temperature of whole blood or plasmaprior to and after processing, and variation in applied centrifugal force. The SOMAscan® assay was performed to measure the relative abundance of 1305 proteins. To determine the effects of variations inpre‐analytical processing, the data was statistically analyzed and the results were used to identify significant changes in protein abundance under each study condition relative to the control condition (samples processed without delay and immediately stored at −80°C). Both low centrifugation force(1300 × g compared to 2500 × g) and blood storage at 0°C for 6 hours resulted in the most significant changes in protein abundance (200 and 148 proteins, respectively, fold change ≥ 1.2, P < 0.05, and FDR < 0.05), while storing immediately processed plasma for 24 hours at 4°C yielded the least changes (28 proteins). The results indicate that blood samples should be immediately processed to plasma and frozen in −80°C without delay in order to preserve sample integrity and to minimize any proteome abundance alterations. The results also provide important information on the discovery of protein abundance changes due to pre‐analytical variability that can be useful in performing effective quality control assessments.Support or Funding InformationThis study was supported with funds from the National Center for Toxicological Research, Food & Drug Administration, Jefferson, Arkansas.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.