Multiplex mini Y short tandem repeat haplotyping using fluorescence energy transfer labeled primers

Abstract

A fluorescence energy transfer (ET) cassette labeled mini Y short tandem repeat (STR) genotyping system is presented. A capillary electrophoretic (CE) microdevice with a cross-injector design is used to determine the fluorescence intensities of ET and single dye-labeled STR amplicons, demonstrating a 2-12 fold higher fluorescence signal of ET cassette labels than the corresponding single dye-labeled ones. Eleven extended haplotype mini Y-STRs using ET cassette labeled primers are constructed, and sensitivity and mixed sample studies are performed. Due to the improved spectroscopic properties of ET labels, multiplex mini Y-STR typing is successful with as low as 30 pg of genomic male DNA, and in the high background of female DNA. These results indicate the practical advantage of ET cassette labels for low copy number and poor-quality DNA STR genotyping to be applied for criminal investigations, paternity testing, and evolutionary studies.