A lateral electrophoretic flow diagnostic assay

Lab Chip. 2015 Mar 21;15(6):1488-96. doi: 10.1039/c4lc01370k.

Abstract

Immunochromatographic assays are a cornerstone tool in disease screening. To complement existing lateral flow assays (based on wicking flow) we introduce a lateral flow format that employs directed electrophoretic transport. The format is termed a "lateral e-flow assay" and is designed to support multiplexed detection using immobilized reaction volumes of capture antigen. To fabricate the lateral e-flow device, we employ mask-based UV photopatterning to selectively immobilize unmodified capture antigen along the microchannel in a barcode-like pattern. The channel-filling polyacrylamide hydrogel incorporates a photoactive moiety (benzophenone) to immobilize capture antigen to the hydrogel without a priori antigen modification. We report a heterogeneous sandwich assay using low-power electrophoresis to drive biospecimen through the capture antigen barcode. Fluorescence barcode readout is collected via a low-resource appropriate imaging system (CellScope). We characterize lateral e-flow assay performance and demonstrate a serum assay for antibodies to the hepatitis C virus (HCV). In a pilot study, the lateral e-flow assay positively identifies HCV+ human sera in 60 min. The lateral e-flow assay provides a flexible format for conducting multiplexed immunoassays relevant to confirmatory diagnosis in near-patient settings.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antibodies, Viral / blood
  • Antibodies, Viral / immunology
  • Antigens, Viral / chemistry
  • Antigens, Viral / immunology
  • Electrophoresis / instrumentation
  • Electrophoresis / methods*
  • Hepatitis C / diagnosis
  • Humans
  • Immobilized Proteins / immunology
  • Immunoassay / instrumentation
  • Immunoassay / methods*
  • Microfluidic Analytical Techniques / instrumentation
  • Microfluidic Analytical Techniques / methods*
  • Molecular Imaging

Substances

  • Antibodies, Viral
  • Antigens, Viral
  • Immobilized Proteins