Increasing the Sensitivity of Enzyme-Linked Immunosorbent Assay Using Multiplexed Electrokinetic Concentrator

• Main Authors: Cheow, Lih Feng (Contributor), Ko, Sung Hee (Author), Kim, Sung Jae (Contributor), Kang, Kwan Hyoung (Author), Han, Jongyoon (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Biological Engineering (Contributor), Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science (Contributor)
• Format: Article
• Language: English
• Published: American Chemical Society (ACS), 2012-09-17T19:02:45Z.
• Subjects: Article
• Online Access: Get fulltext

We developed a novel method to increase the sensitivity of standard enzyme-linked immunosorbent assay (ELISA) using a multiplexed electrokinetic concentration chip. The poly(dimethylsiloxane) (PDMS) molecular concentrator(1) was used to trap and collect charged fluorescent product of target-bound enzyme turnover reaction of ELISA that occurred in a standard 96 well plate. Detection sensitivities of both prostate specific antigen (PSA) and CA 19-9 (a human pancreatic and gastrointestinal cancer marker) ELISAs in serum are enhanced ~100 fold with a low CV of <17%. We also integrated this method with an on-chip bead-based ELISA that lends itself toward a fully automated on-chip diagnostic device. Detection sensitivity of microfluidic bead-based CA 19-9 ELISA in serum is enhanced ~65 fold compared to the results without the electrokinetic accumulation step. This chip can be directly applied to enhance the readout sensitivity of a wide range of existing ELISA kits at concentrations below the current detection limit.
National Institutes of Health (U.S.) (CA119402)
National Institutes of Health (U.S.) (EB005743)