Microchip capillary gel electrophoresis with electrochemical detection for the analysis of known SNPs

A novel microchip-based single nucleotide polymorphism (SNP) screening system has been developed. The system utilizes capillary gel electrophoresis (CGE) with electrochemical detection in a chip-based format to accomplish rapid scoring of a mock SNP site. The accuracy of the thermostable polymerase and the advantages of coupling this technique to microfluidics are demonstrated. An electrochemically labeled chain terminator is used in the single base extension (SBE) reaction, in which the terminator is incorporated only when its Watson-Crick complementary base is present at the mock SNP site. The resulting electrochemically active extension product is subsequently separated from any excess terminator by CGE and detected by sinusoidal voltammetry. Although no attempts at optimization have been made, the analysis is performed in less than 4 min. The technique presented could lead to a fast, simple, and cost effective SNP scoring system.