Holographic immunoassays

TL;DR

Holographic immunoassays utilize changes in probe bead size from holographic particle characterization to measure molecular binding kinetics, enabling rapid, quantitative antibody detection in solution.

Contribution

This paper demonstrates the use of holographic particle characterization for real-time, quantitative immunoassays of antibody binding kinetics and concentrations.

Findings

Measured binding rates of IgG and IgM antibodies.

Validated the technique for quantitative antibody detection.

Showed potential for rapid immunoassays.

Abstract

The size of a probe bead reported by holographic particle characterization depends on the proportion of the surface area covered by bound target molecules and so can be used as an assay for molecular binding. We validate this technique by measuring the kinetics of irreversible binding for the antibodies immunoglobulin G (IgG) and immunoglobulin M (IgM) as they attach to micrometer-diameter colloidal beads coated with protein A. These measurements yield the antibodies' binding rates and can be inverted to obtain the concentration of antibodies in solution. Holographic molecular binding assays therefore can be used to perform fast quantitative immunoassays that are complementary to conventional serological tests.