DNA TYPING IN 30 SECONDS WITH A MICROFABRICATED DEVICE

We report the development of a practical ultrafast allelic profiling a ssay for the analysis of short tandem repeats (STRs) by using a highly optimized microfluidic electrophoresis device. We have achieved basel ine-resolved electrophoretic separations of single-locus STR samples i n 30 sec. Analyses of PCR samples containing the four loci CSF1PO, TPO X, THO1, and vWA (abbreviated as CTTv) were performed in less than 2 m in. This constitutes a 10- to 100-fold improvement in speed relative t o capillary or slab gel systems. The separation device consists of a m icrofabricated channel 45 mu m x 100 mu m in cross section and 26 mm i n length, filled with a replaceable polyacrylamide matrix operated und er denaturing conditions at 50 degrees C, A fluorescently labeled STR ladder was used as an internal standard for allele identification. Sam ples were prepared by standard procedures and only 4 mu l was required for each analysis. The device is capable of repetitive operation and is suitable for automated high-speed and high-throughput applications.