www.sipr.ac.uk

Transcript www.sipr.ac.uk

New DNA developments better, faster and cheaper

Better – new multiplexes

ENFSI Requirement Robust multiplexes, inc. Mini STRs • Fifteen STR loci – Ten SGM Plus ® loci, FGA, TH01, VWA, D3S1358, D8S1179, D18S51, D21S11, D2S1338, D16S539, D19S433 – Additional 5 loci D1S1656, D2S441, D10S1248, D12S391, D22S1045 – Amelogenin • ENFSI DNAWG December 2009 – Expansion of ESS to include additional 5 loci. © Forensic Science Service Ltd. 2010. All rights reserved.

Size /bp

Strategic multiplexing • Choice of PowerPlex® multiplexes • ESX-16 & ESX-17 – Standard size “SGMPlus ®” loci • ESI-16 & ESI-17 – “Mini” SGMPlus ® loci • Optimised for 500pg DNA and 30 cycles • Applied Biosystems NGM • BioType Mentype® ESSplex © Forensic Science Service Ltd. 2010. All rights reserved.

Evaluation of Performance

Sensitivity

1 locus

DNA Template (pg)

Inhibitors

Humic Acid

Humic Acid

SGM+ SGM+ MiniFiler SGM+ ESX 16 ESX-16 ESI-16

SGM+ SGM+ MiniFiler SGM+ ESX -16 ESX-16 ESI-16

Degraded DNA

Degraded DNA Sample Degraded FSS UV1 FSS UV2 ENZ 10’ ENZ 15’ UV sem ESX ESI SGM+ 16 loci 11 loci 16 loci 11 loci 11 loci 56% 38% 38% 27% 63% 34% 86% 50% 33% 0% 16% 65% 42% ND 9% 64% 36% ND 28% 65% 58% 100% 41% 86% 77% 100% ND 59% 36% 76% © Forensic Science Service Ltd. 2010. All rights reserved.

Degradation

Amp of SGMPlus® Loci with degraded DNA

120 100 80 60 40 20 0 Deg FSS UV1 FSS UV2 Enz 10

Sample

Concordance

NIST Concordance with Identifiler ® 1461 samples • ESX-16 – 4 loci discordant – 99.98% concordance • ESI-16 – 3 loci discordant – 99.98% concordant © Forensic Science Service Ltd. 2010. All rights reserved.

FSS Concordance with SGMPlus ® ESX 16 ESI 16 Number of loci compared Number of concordant loci Concordance (%) 3500 3498 99.94

3500 3499 99.97

Summary • Promega ES multiplexes – Sensitive – Robust to inhibitors – ESI “SGMPlus” loci very robust with degraded DNA – High level of concordance with NIST samples © Forensic Science Service Ltd. 2010. All rights reserved.

Next steps: • For new multiplexes meeting the ENFSI requirement: – Gain acceptance to NDNAD – Concordance • (ESX vs ESI vs SGMPlus® vs NGM vs ESSplex) – Frequency databases – Check for independence (product rule) © Forensic Science Service Ltd. 2010. All rights reserved.

Faster - Custody suite DNA testing Development of a forensically integrated DNA analysis system.

Introduction • What is the aim?

Requirement Eliminate submission by processing at POC • Environment – deployment • Operator – Skill – Training • Outcome – DNA profile loaded to the NDNAD – Match reported in Real Time • Robust • Simple User Interface • Automated – Chemistry – Analysis – Database search • 2h turn round • Evidential quality © Forensic Science Service Ltd. 2010. All rights reserved.

How does it work?

V V V V V V V V V Direct to PCR Chamber Magnet

TH01

What we will achieve in the future • Integrated lysis vial • Single cartridge – Plastic CE • Reduce time to <2h Sample to match • Multiple samples – Maintain sample integrity • Casework samples © Forensic Science Service Ltd. 2010. All rights reserved.

Review • Simple set up • Self contained cartridge • Minimised opportunity for contamination; batch control • Full 16-plex DNA profiles with no manual intervention • Identified requirement for further work (in progress) • Software/database solutions essential for benefit realisation © Forensic Science Service Ltd. 2010. All rights reserved.

How does DNA interpretation work and why is it suboptimal?

DNA is visualised as a signal referred to as an EPG.

The role of the scientist is to translate the signal into a simple set of paired numbers that define the DNA profile. These numbers are then compared between profiles in a case (suspect to crimestain) or through the National DNA Database.

Issue 1: Complex data are impossible to convert into a simple set of paired numbers.

16 20 24 26 Issue 2: A high proportion of reporting officer interpretation work is performed manually.

Where does DNAboost fit into all this?

DNAboost, in part, addresses Issue 1: “Complex data are

impossible to convert into a simple set of paired numbers”

by a simple improvement to the database design.

DNAboost improves the search and match rate for DNA intelligence and demonstrates that improved encoding of data is a key way of improving performance.

15 17 15 18 17 18 15 15 17 17 18 18 DNAboost was always intended to be a development milestone towards improved coding, searching and matching.

Issue 2: “A high proportion of reporting officer interpretation work is performed

manually”

remains largely unimproved and has opportunities for improvements in efficiency, response time, effectiveness and quality.

How could DNA interpretation be further improved?

The current approach always discards useful information that may be required for case assessment, intelligence or troubleshooting.

Manual ‘best guess’ 18, 16, 11

informatio n.

National DNA Database or interp process Lost information.

Needs manual, paper review later in the process.

The answer is to develop a new interpretation approach that always retains and uses all the useful information. This requires ‘whole EPG interpretation’.

~80,000 pieces of information.

Design and deployment of the new interpretation model

– – – Interprets batches of DNA data to confirm validity.

Software-based.

Partially automated.

– – – Interprets cases of DNA data to form opinion.

Paper-based.

(Very) manual.

Guideline-based and artisan(?) Valid paper data Expert opinion Reporting Officer

FSS DNA INSIGHT design

– – – – Software to interpret DNA data Server to regularise and disseminate DNA data FSS DNA INSIGHT Server to control settings and administration Science, publication, validation, process, training and support Reporting Officer

Better, faster, cheaper • The new chemistries may increase timeliness through higher first pass success rates with a reduced requirement for specialist methods like LCN • Custody suite testing may reduce total forensic supply chain costs.

• DNA INSIGHT may increase success rates through the improved interpretation models.