A multi-function, microfluidic module for mutation detection

A multi-function, microfluidic module was designed, fabricated, and used for mutation detection using the ligase detection reaction (LDR) following amplification by the polymerase chain reaction (PCR). The module carried out four processing steps: (1) the PCR to amplify a target region in the K-ras gene of the human genome, which can lead to colorectal cancer; (2) the purification of the PCR products; (3) the mixing of the purified PCR products with an LDR reagent using a passive micromixer; and (4) the LDR to make florescent oligonucleotide products detectable by gel electrophoresis. Single nucleotide polymorphisms in the K-ras gene were detected from a concentration ratio of mutant to normal genomic DNA of 1:40 using the multi-function, microfluidic module.