Advection-enhanced kinetics in microtiter plates for improved surface assay quantitation and multiplexing capabilities

TL;DR

WellProbe introduces a microfluidic approach compatible with standard microtiter plates, significantly enhancing surface assay sensitivity, speed, and multiplexing capabilities by overcoming traditional mass transport limitations.

Contribution

It presents a novel microfluidic device, WellProbe, that improves assay kinetics and multiplexing in microtiter plates without disrupting existing protocols.

Findings

Up to 9-fold increase in signal sensitivity

Assay time reduced by 12-fold

Enabled multiplexing with 3-4 kinetic conditions

Abstract

Surface assays such as ELISA are pervasive in clinics and research and predominantly standardized in microtiter plates (MTP). MTPs provide many advantages but are often detrimental to surface assay efficiency due to inherent mass transport limitations. Microscale flows can overcome these and largely improve assay kinetics. However, the disruptive nature of microfluidics with existing labware and protocols has narrowed its transformative potential. We present WellProbe, a novel microfluidic concept compatible with MTPs. With it, we show that immunoassays become more sensitive at low concentrations (up to 9-fold signal improvement in 12-fold less time), richer in information with 3-4 different kinetic conditions, and can be used to estimate kinetic parameters, minimize washing steps and non-specific binding, and identify compromised results. We further multiplex single-well assays combining WellProbes kinetic regions with tailored microarrays. Finally, we demonstrate our system in a context of immunoglobulin subclass evaluation, increasingly regarded as clinically relevant.