What is NGS?
- utilises DNA sequencing technologies that can manage many DNA sequences at once
- high sensitivity
- capability to small amounts of DNA
- aged or compromised samples
What is NGS also known as?
massively parallel DNA sequencing (MPS)
The National DNA Database statisicts
- only a small team in the Home Office have access to it
- largest in Europe
- police will only get a notification if they have a match they do not have access to it
How does MPS work?
- not only looks at the lengths of each DNA fragment but also the specific DNA sequence each fragment contains
- multiple DNA tests in one assay - no need to consider how to portion out DNA extract
- backwards compatible with NDNAD
Why is MPS better than DNA 17?
it can work when there isnt sufficient information to search NDNAD or if there is no match on the NDNAD
What is the first next generation sequencing instrument called which is developed and validated for forensic genomics?
MiSeq FGx Sequencing System
What are the biological steps in MPS?
- DNA extraction
- DNA quantitation
- PCR amplification of multiple loci
What are the technological steps when using MPS?
- library preparation and sequencing of amplified product
- DNA sample genotype determination
What are the applications when using MPS?
- compare simple genotype to reference crime samples
- compare DNA profiles to population databases
- generate reports using statistics RMP/LR
Why is MPS more differentiating than DNA 17?
looks at 230 markers compared to 34 markers in DNA 17
How do we decide what type of SNP sequencing to use?
depends on the quality and quantity on DNA
What are the three SNP sequencing options
- SNP microarray
- targeted kit: kintelligence
- whole genome sequencing
What is SNP microarray?
- ~600,000 SNP’s
- ~200ng
- most inexpensive
- not good with degraded DNA
What is kintelligence?
- ~10,230 SNPs
- > 50pg - 1ng
- mid range cost
- future, in house crime lab capacity
What is whole genome sequencing?
- > 1 million SNPs (not the whole genome)
- > 50pg
- most expensive
- recommended for degraded DNA
What are the benefits of the ForenSeq DNA Signature Prep Kit (Verogen)?
- eliminate the need for multiple STR kits
- interrogate 200 genetic markers using a single, streamlined workflow
- access a wider range of informative SNPs
- multiplexing and rapid sample processing
- prepare up tp 96 genomic libraries simultaneously using a simple plate-based format and standard lab equipment
- great with complex mixtures or degraded DNA
- can discriminate data from less than 100pg
What is a microvarient?
alleles that contain an incomplete repeat unit, often complicate the process of DNA analysis
What is the ForenSeq DNA Signature Prep Kit (Verogen)?
the kit used for preparing DNA samples for MPS
What is benefical about being able to see greater allelic detail when using MPS?
- can see if there are any microvarients occuring within the repeats
What is eye and hair colour determined by?
phenotyping
What is next for MPS?
- increased prediction capabilities in skin colour, ancestry, age of doner (blood, bone, semen)
- investigative genetic genealogy
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DNA Structure35
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Stability and Handling19
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Electrophoresis11
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Synthesis18
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PCR23
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Profiling and Sequencing17
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DNA Analysis and Interpretation35
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Practical DNA Processing57
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How to generate DNA profiles25
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Benefits of New Multiplexes23
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Interpretation of Single Source DNA Profile6
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Mixtures and Incomplete DNA Profiles29
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Next Generation Sequencing21
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Contamination25
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Artefacts and Noise38
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Forensic Geneaology19
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Bone samples13
