Performance of the RapidHIT™200

Abstract

RapidHIT™200 (IntegenX) is an all-in-one instrument built to produce STR profiles of reference samples (buccal swabs) in 90min with minimal hands-on time. The aim of this study was to investigate the performance of the RapidHIT™200 with regards to analysis of buccal swabs and to explore the possibilities of employing the instrument for analysis of more challenging sample formats than buccal swabs. Mouth swabs gave 74% full STR profiles with correctly assigned alleles. Full STR profiles were obtained with dilutions of lymphocyte DNA spotted onto cotton swabs with a range of 900–1200ng DNA. With lower and higher amounts of DNA, drop-outs of alleles and loci were observed. There was no obvious correlation between the amounts of input DNA and the peak heights of the alleles in the profiles. However, when the peak height was low, the risk of obtaining a partial profile was increased. A piece of muscle from an identification case from 2007 was thawed and rubbed with cotton swabs for 10, 20 and 40s. The rapidHIT™200 analyses gave partial STR profiles corresponding to a degradation pattern with correctly assigned alleles. In general, STR alleles were assigned correctly and the muscle experiment was promising. There was no correlation between input DNA and peak height. The sensitivity of the RapidHIT™200 is lower than those of conventional STR typing methods.