Optimized magnetic bead-based immunoassay for automated detection of protein toxins

Rapid, accurate, and autonomous analysis of bioagents in the environment is critical in protecting human health from natural and intentional environmental contamination with biological toxicants. We previously developed and tested an immunoassay protocol that can be utilized for automated and simultaneous detection of selected biological agents and toxins. We adopted an antibody-based approach for the detection of pathogens and/or toxins. The fluorescent eTags™ were used as reporter molecules and the immunoassay was modified for automated field-deployed detection of pathogens and/or toxins. The present study improved the limit of detection of this system to be suitable for the detection of environmental toxins. We tested different settings to optimize the assay protocol and successfully detected 10 ng/mL (or 100 fg) of an toxin analog, ovalbumin. The developed assay represents a notable improvement from currently available assays in terms of reduced time, increased sensitivity, and automation potential. Additionally, this assay can be easily modified, with the appropriate antibodies, to detect a wide range of proteins and infectious agents.