Rapid, parallel separations of D1S80 alleles in a plastic microchannel chip

We have performed fast, parallel separations of alleles of the D1S80 locus in a plastic, multi-channel chip, replicated from a microfabricated master and laminated with a plastic film. The array of 16 channels was filled with a replaceable sieving polymer, and a size-dependent, electrophoretic separation of the DNA fragments was performed in all channels in less than 10 min, representing a 30-fold increase in throughput compared to that on a single-capillary instrument. To detect the fragments in all 16 channels in parallel during the run, we designed and built a scanning, confocal, laser-induced fluorescence system. The electropherograms were then used to determine the sample genotype. To demonstrate the use of multiplexed, microchannel arrays for real-life samples, we amplified D1S80 alleles from genomic DNA extracted from whole blood and separated these alleles by electrophoresis in the plastic chip. Evaluation of the electrophoretic data showed that, using a 300- and a 1000-base pair fragment as internal mobility markers, 83% of the alleles were assigned correctly, using the allele identification from a single capillary instrument as a reference. This work demonstrates that, with improvements in the microchannel electrophoresis system, it is feasible to perform rapid, parallel genotyping in mass-produced, inexpensive, disposable plastic devices for large-scale applications in medicine and the life sciences.