Efficient screening of high-signal and low-background antibody pairs in the bio-bar code assay using prion protein as...

The bio-bar code assay is an assay for ultrasensitive detection of proteins. The main technical hurdle in bio-bar code assay development is achieving a dose-dependent, reproducible signal with low background. We report on a magnetic bead ELISA screening mechanism for characterizing antibody pairs that are effective for use in the bio-bar code assay. The normal isoform of prion protein was utilized as the target protein as dozens of antibodies have been developed against it. The development of an ultrasensitive assay for the detection of the various isoforms of PrP has the potential to enable significant advances in the diagnosis and understanding of transmissible spongiform encephalopathies, including transmission mechanisms, disease pathology, and potential therapeutics. With prion protein as the target, the magnetic bead ELISA identified pairs with high background and low signal in the bio-bar code assay. The magnetic bead ELISA was effective as a screening mechanism because it reduced assay time and cost and allowed for understanding of pair characteristics such as development times and signal-to-noise ratios.