%0 Journal Article %A Bauer, Westley S. %A Gulka, Christopher P. %A Silva-Baucage, Lidalee %A Adams, Nicholas M. %A Haselton, Frederick R. %A Wright, David W. %D 2017 %T Metal Affinity-Enabled Capture and Release Antibody Reagents Generate a Multiplex Biomarker Enrichment System that Improves Detection Limits of Rapid Diagnostic Tests %U https://acs.figshare.com/articles/journal_contribution/Metal_Affinity-Enabled_Capture_and_Release_Antibody_Reagents_Generate_a_Multiplex_Biomarker_Enrichment_System_that_Improves_Detection_Limits_of_Rapid_Diagnostic_Tests/5425621 %R 10.1021/acs.analchem.7b01513.s001 %2 https://acs.figshare.com/ndownloader/files/9360886 %K p LDH CaR antibody reagents %K beads %K Plasmodium lactate dehydrogenase %K Multiplex Biomarker Enrichment System %K Multiplex biomarker enrichment %K CaR antibody reagent %K Rapid Diagnostic Tests Multi-antigen %K flow malaria RDT %K Release Antibody Reagents Generate %K HRPII %K metal affinity %K p LDH %K CaR antibody reagents %K bead-based multiplex biomarker enrichment strategy %K Plasmodium falciparum parasitized blood samples %K POC %K sample processing system %K targets Plasmodium falciparum histidine-rich protein-II %K metal Affinity-Enabled Capture %X Multi-antigen rapid diagnostic tests (RDTs) are highly informative, simple, mobile, and inexpensive, making them valuable point-of-care (POC) diagnostic tools. However, these RDTs suffer from several technical limitationsthe most significant being the failure to detect low levels of infection. To overcome this, we have developed a magnetic bead-based multiplex biomarker enrichment strategy that combines metal affinity and immunospecific capture to purify and enrich multiple target biomarkers. Modifying antibodies to contain histidine-rich peptides enables reversible loading onto immobilized metal affinity magnetic beads, generating a novel class of antibodies coined “Capture and Release” (CaR) antibody reagents. This approach extends the specificity of immunocapture to metal affinity magnetic beads while also maintaining a common trigger for releasing multiple biomarkers. Multiplex biomarker enrichment is accomplished by adding magnetic beads equipped with CaR antibody reagents to a large sample volume to capture biomarkers of interest. Once captured, these biomarkers are magnetically purified, concentrated, and released into a RDT-compatible volume. This system was tailored to enhance a popular dual-antigen lateral flow malaria RDT that targets Plasmodium falciparum histidine-rich protein-II (HRPII) and Plasmodium lactate dehydrogenase (pLDH). A suite of pLDH CaR antibody reagents were synthesized, characterized, and the optimal CaR antibody reagent was loaded onto magnetic beads to make a multiplex magnetic capture bead that simultaneously enriches pLDH and HRPII from Plasmodium falciparum parasitized blood samples. This system achieves a 17.5-fold improvement in the dual positive HRPII/pan-pLDH detection limits enabling visual detection of both antigens at levels correlating to 5 p/μL. This front-end sample processing system serves as an efficient strategy to improve the sensitivity of RDTs without the need for modifications or remanufacturing. %I ACS Publications