A method to study protein biomarkers in saliva using an automated capillary nano-immunoassay platform (Wes™)

Traditional immunoprobing techniques like Western blot continue to play a crucial role in the discovery and validation of biomarkers. This technique suffers from several limitations that affect reproducibility and feasibility for large-scale studies. Modern immunoprobing techniques have addressed several of these limitations. Here we contrast the use of Western blot and an automated capillary nano-immunoassay (CNIA), Wes™. We provide evidence highlighting the methodological advantages of Wes™ over Western blot in the validation of a novel biomarker, Calcium-binding protein and spermatid-associated 1 (hCABS1). While Wes™ offers a faster, more consistent approach with lower requirements for sample and antibody volumes, variations in expected molecular weights and computational algorithms used to analyze the data must receive careful consideration and assessment. Our data suggests that CNIA approaches are likely to positively impact biomarker discovery and validation. •We analyzed levels of hCABS1 in saliva in a study of acute stress.•We used capillary nano-immunoprobing assay Wes™ and compared it to Western blot.•Wes™ replicates previous Western blot results of elevated hCABS1 in acute stress.•Wes™ has higher sensitivity, specificity, throughput, uses less sample and antibody volumes.•This extends our previous evidence that saliva hCABS1 is a biomarker of stress.