Fast, sensitive bioassays with microfluidics preconcentration of samples

Researchers in Prof. Juan Santiago's laboratory have developed a technique to rapidly preconcentrate and capture biological targets with high specificity and efficiency. The process can be used to reduce reaction times for microarray analyses and affinity chromatography. The protocol includes isotachophoresis (ITP) to selectively focus target molecules as well as other strategies to achieve high efficiency capture of target. Specifically, the liquid phase is quickly displaced using gas flow to preserve the high capture rate achieved during a brief ITP reaction. The process increases sensitivity of assays and reduces the total ligand needed for detection and purification, thereby decreasing the cost of the assay. This microfluidics invention could be coupled with a variety of assays for rapidly purifying, detecting and analyzing proteins or nucleic acids for SNP analyses, biomarker discovery, or clinical diagnostics.

Stage of Research
The inventors have demonstrated ITP preconcentration with affinity chromatography by purifying a 25nt target DNA from 10,000-fold higher abundance background in less than 10 minutes. In an ITP-microarray experiment, the inventors showed 8.2-fold higher signal in a 30 minute assay (compared to conventional overnight hybridization) with rapid and quantitative detection over 4 orders of magnitude dynamic range.