VersaPlex® 27PY System

Overview

Short tandem repeat (STR) loci are well distributed throughout the human genome and can be detected using the polymerase chain reaction (PCR). Alleles of STR loci are differentiated by the number of copies of the repeat sequence contained within the amplified region. They can be distinguished from one another using fluorescence detection following electrophoretic separation.

The VersaPlex® 27PY System is a 6-color, 27-loci multiplex STR amplification system capable of rapid cycling. In addition to the D6S1043 locus, the kit includes: CSF1PO, FGA, TH01, TPOX, vWA, D1S1656, D2S441, D2S1338, D3S1358, D5S818, D7S820, D8S1179, D10S1248, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, D22S1045, Penta D, Penta E, DYS391, DYS570, DYS576 and Amelogenin.

Promega forensic products are manufactured in alignment with the ISO 18385 standard.This standard ensures minimal risk of human DNA contamination for products used to collect, store and analyze biological materials for forensic purposes. Learn more.

Superior Discrimination

The VersaPlex® loci offer Probability of Identity (PI) values of 4.4 × 10^–30 for four combined American populations and 6.2 × 10^–27 for the Asian-American population.^† Eleven loci are under 250bp, making the kit useful for degraded samples.

^†Butler, J.M. et al. (2012) Variability of new STR loci and kits in US population groups. Profiles in DNA.

Configuration of the VersaPlex 27PY System — **Configuration of the VersaPlex® 27PY System.** The VersaPlex® 27PY System allows co-amplification and detection of 27 loci, including: D3S1358, D1S11656, D2S441, D10S1248, D13S317, D16S539, D18S51, D2S1338, CSF1P0, TH01, vWA, D21S11, D7S820, D5S818, TP0X, D8S1179, D12S391, D19S433, D6S1043, D22S1045, FGA, DYS391, as well as DYS576, DYS570, Penta D, Penta E and Amelogenin.

Improved Interpretation of Complex Mixtures

Like other CODIS-compliant kits, the DYS391 locus is included for gender verification of Amelogenin-null samples. Additionally, the kit includes two Y-STR loci with high gene diversity values, DYS570 and DYS576. These three Y-STR loci enable more confident determination of the number of male contributors in complex mixtures for even the most difficult casework samples.

Y-STR	Number of Alleles^a	Gene Diversity^a	Mutation Rate^b
DYS391	10	0.521	5/1759	3.23 × 10^–3
DYS576	21	0.789	24/1727	1.43 × 10^–2
DYS570	28	0.803	17/1429	1.24 × 10^–2
a. Purps, J. et al. (2014) A global analysis of Y-chromosomal haplotype diversity for 23 STR loci. Forensic Sci. Int. Genet. 12, 12. b. Ballantyne, K. et al. (2010) Mutability of Y-chromosomal microsatellites: rates, characteristics, molecular bases, and forensic implications. Am. J. Hum. Genet. 87, 341.

In the figure below, both male contributors have the same DYS391 allele. Conversely, both the DYS576 and DYS570 loci indicated that there are two male contributors, demonstrating how the inclusion of the additional Y-STR loci can enable improved mixture interpretation.

**Electropherogram of a three-person mixture.** A complex three-person DNA mixture with 45pg each of two different minor male contributors and one major female contributor (1ng total) was amplified for 29 cycles. Amplified samples were separated on a 3500xL Genetic Analyzer using a 1.2kV 24-second injection. Data were analyzed with GeneMapper® *ID-X* software.

Wide Range of Sample Inputs

While optimized at 1ng of input DNA, the VersaPlex® 27PY System can handle a wide range of input amounts. The figures below show that the VersaPlex® 27PY System generated a complete, balanced profile at twice the recommended input DNA concentration compared to a competitive kit that exhibited saturation at twice its recommended input.