Eurofins Forensic Services provides DNA profiling services to the 43 territorial police forces in England and Wales, processing over 300,000 reference samples and up to 100,000 crime samples per year. Many of these profiles are loaded to or searched against the UK National DNA database (NDNAD), which now comprises over 7.2 million subject profiles and 688,000 crime scene profiles (March 2024). The standard STR chemistry for the database has been 16 locus STR systems since 2014.
Since 2014, commercial STR systems have continued to develop, with increasing numbers of loci, addition of Y-STR markers into autosomal kits, internal quality standards and more fluorescent dyes. Recent developments include the 8-dye channel Spectrum CE (Promega) and a portfolio of 8-dye kits for this instrument, including the unreleased Powerplex 27GY kit utilising a novel low-stutter polymerase.
This study assesses the performance of three of these new Promega 8-dye STR kits (PowerPlex 18E and PowerPlex 35GY) against the standard processes used for many years at high throughput in our casework laboratory.
Chemistries were assessed for sensitivity using dilution series of known samples and their ability to recover allelic data from weak or degraded samples along with performance of internal quality markers. The ability of each kit to produce profiles meeting the NDNAD load criteria was compared with reference to locus positions and amplicon sizes across the dye sets. To provide means of comparison the same samples were also amplified with the current 5-dye STR chemistry (PowerPlex ESI 17 Fast), with resulting PCR products analysed on both the Spectrum and 3500XL (Thermo Fisher) CE instrumentation.
A set of ground-truth DNA mixtures, and artificially degraded DNA samples have been run to investigate the potential benefits of the reported increased dynamic range of the Spectrum CE. The ability to “overload” the instrument with excess PCR product allows much greater peak-heights without “peak-capping” which we demonstrate enhanced detection of low-level alleles in degraded samples.
Other features of the Spectrum CE instrument will also be discussed with respect to workflow integration.
Eurofins Forensic Services provides DNA profiling services to the 43 territorial police forces in England and Wales, processing over 300,000 reference samples and up to 100,000 crime samples per year. Many of these profiles are loaded to or searched against the UK National DNA database (NDNAD), which now comprises over 7.2 million subject profiles and 688,000 crime scene profiles (March 2024). The standard STR chemistry for the database has been 16 locus STR systems since 2014.
Since 2014, commercial STR systems have continued to develop, with increasing numbers of loci, addition of Y-STR markers into autosomal kits, internal quality standards and more fluorescent dyes. Recent developments include the 8-dye channel Spectrum CE (Promega) and a portfolio of 8-dye kits for this instrument, including the unreleased Powerplex 27GY kit utilising a novel low-stutter polymerase.
This study assesses the performance of three of these new Promega 8-dye STR kits (PowerPlex 18E and PowerPlex 35GY) against the standard processes used for many years at high throughput in our casework laboratory.
Chemistries were assessed for sensitivity using dilution series of known samples and their ability to recover allelic data from weak or degraded samples along with performance of internal quality markers. The ability of each kit to produce profiles meeting the NDNAD load criteria was compared with reference to locus positions and amplicon sizes across the dye sets. To provide means of comparison the same samples were also amplified with the current 5-dye STR chemistry (PowerPlex ESI 17 Fast), with resulting PCR products analysed on both the Spectrum and 3500XL (Thermo Fisher) CE instrumentation.
A set of ground-truth DNA mixtures, and artificially degraded DNA samples have been run to investigate the potential benefits of the reported increased dynamic range of the Spectrum CE. The ability to “overload” the instrument with excess PCR product allows much greater peak-heights without “peak-capping” which we demonstrate enhanced detection of low-level alleles in degraded samples.
Other features of the Spectrum CE instrument will also be discussed with respect to workflow integration.
Workshop currently at capacity. A waitlist is available to join on our registration page.
Technical Specialist, Eurofins Forensic Services DNA Centre
Aimee Hack is a Technical Specialist for the Eurofins Forensic Services DNA Centre in the UK where she has worked since 2011. She has a BSc in Forensic Science from the University of Central Lancashire. As part of the Technical Team, she is responsible for implementation and evaluation of new technologies in the high throughput process lines used in the DNA Centre for processing reference and crime samples.
