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Recovering DNA following fingerprint treatments

Investigating the effects of Foster + Freeman fingerprint treatments on DNA analysis. Independent tests show that PolyCyano UV treatment does not interfere with DNA profiling, while TFD-2 treatment reduces the possibility of recovering DNA for identification. November 2011.

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Recovering DNA following fingerprint treatments

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  1. Recovering DNA following fingerprint treatmentsNovember 2011Independent tests carried out by the Forensic Science Service

  2. Forensic scientists can use DNA in blood, semen, skin, saliva, hair, or fingerprint residues found at a crime scene to identify a matching DNA of an individual. This study investigates the effects that Foster + Freeman fingerprint treatments, Thermal Fingerprint Development (TFD-2) and PolyCyano UV fuming, have on subsequent DNA analysis Brochure TFD-2 Brochure PolyCyano Brochure Fingerprints range

  3. TFD-2Thermal Fingerprint Developer A simple, low-cost, chemical-free method for fingerprint detection and visualisation. Method Uniform heating of documents causes a chemical reaction between the latent fingerprint and the paper. This produces a fluorescent by-product which is visible under intense visible light (Crime-lite Blue or Crime-lite Blue/Green with appropriate filters) Brochure TFD-2 Brochure PolyCyano Brochure Fingerprints range Equipment

  4. MVC/Dcyanoacrylate fuming cabinets Updated superglue fuming cabinets for the controlled development of latent fingerprints Method Operated under automatic or manual control MVC/D cabinets heat PolyCyano to its evaporation point of 230oC. PolyCyano reacts with amino acids in the latent fingerprint and moisture in the air to produce a sticky white material that forms along the ridges of any fingerprints present. Brochure TFD-2 Brochure PolyCyano Brochure Fingerprints range Equipment

  5. PolyCyano UVOne-stage Development A new glue/stain process for developing fingerprints without the need for further chemical treatment. Method Designed for use with dual temperature MVC/D fuming cabinets PolyCyano UV requires heating to 230oC. Once evidence has been fumed it is ready for examination under a longwave 365nm UV light source such as the Crime-lite 82S UV. Brochure TFD-2 Brochure PolyCyano Brochure Fingerprints range Equipment

  6. Crime-litecomplete range of high intensity LED forensic light sources For the fluorescence examination of evidence both at the crime scene and laboratory. Method Crime-lite light sources are used to visualise the fluorescent emmissions of fingerprints following treatment with the TFD-2 or PolyCyano UV Brochure TFD-2 Brochure PolyCyano Brochure Fingerprints range Equipment

  7. ? ? ? ? ? • 5 DNA donors were selected at random • Each donor provided: • 1 control sample (mouth swab) • 8 samples for TFD-2 analysis • 6 samples for PolyCyano analysis • Precautions were taken to avoid • contamination Brochure TFD-2 Brochure PolyCyano Brochure Fingerprints range DNA donors

  8. TEST: PolyCyano 2 glass slides acted as a control 2 glass slides were treated with PolyCyano using a MVC/D cabinet 2 glass sides were treated with PolyCyano UV using a MVC/D cabinet and then cured with a Crime-lite 82S UV RESULTS In the untreated test 10 out of 10 (100%) yielded a full DNA profile In both variations of the PolyCyano UV treated test 10 out of 10 results (100%) yielded a full DNA profile Brochure TFD-2 Brochure PolyCyano Brochure Fingerprints range PolyCyano UV Test

  9. TEST: TFD-2 A total of 40 samples were analysed 20 samples on paper acted as a control 20 samples on paper were processed using the TFD-2. Speed 2000mm/min, Power 100% RESULTS In the untreated test 20 out of 20 (100%) yielded a full DNA profile In TFD-2 treated test 6 out of 20 (30%) yielded a full DNA profile Brochure TFD-2 Brochure PolyCyano Brochure Fingerprints range TFD-2 Test

  10. Conclusions PolyCyano UV treatment does not interfere with DNA profiling with 100% of DNA donors identified from treated samples. TFD-2 treatment interferes with DNA profiling, reducing the possibility of recovering DNA which can be used for identification to 30%. Brochure TFD-2 Brochure PolyCyano Brochure Fingerprints range Conclusions

  11. Foster + Freeman Ltd 2011

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