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The impact of fingerprint reagent – cyanoacrylate on DNA. 8 th International Symposium on Forensic Sciences Šamorín – Čilistov september 27 th 2007 Zuzana Deščíková. Aims of the presentation.
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The impact of fingerprint reagent – cyanoacrylate on DNA 8th International Symposium on Forensic Sciences Šamorín – Čilistov september 27th 2007 Zuzana Deščíková
Aims of the presentation • To describe an influence of fingerprint enhancement reagent – cyanoacrylate on DNA and to show, that it has no deleterious effect on DNA
Structure of presentation 1. History 2. Reality 3. Problem 4. Question 5. Cyanoacrylate 6. DNA analysis 7. Fingerprints or DNA? 8. Conclusion
1. History • Ancient fingerprints • Fingerprint pioneers • M.Malpighy • J.E.Purkinje • Sir W. Herschel • H. Faulds • A. Bertillon • Sir F. Galton • Sir Henry • Enhancement of latent fingerprints
2. Reality • Evidence from the crime scene • Selection of the right method • Order of expertise
3. Problem • Persistance of fingerprint / DNA • Factors influencing the fingerprints • Time
Facts • Year 2005 3227 cases 3% together with DNA analysis • Year 2006 2931 cases 2,5% together with DNA analysis • Year 2007 2178 cases 5% together with DNA analysis 90% of these expertises was delayed app. for about 3 months
4. Question • Do chemicals and methods used in dactyloscopy have negative influence on DNA? • Is it possible to make fingerprint analysis BEFORE the DNA analysis? • How does cyanoacrylate influence the DNA?
5. Cyanoacrylate • „Superglue“ or „Krazy glue“ • Ethyl-2-cyanoacrylate • CA fumes react with amino acids • Use for smooth, nonporous surfaces
6. DNA analysis • Same task as dactyloscopy- individual identification • identification of suspects • exoneration of persons wrongly accused of crime • DVI • establishing of the paternity etc. • Serological analysis - RFLP – PCR using STR • Smaller samples, more sensitive analysis
7. Fingerprints or DNA? • Destructive influence of fingerprint enhancement chemicals on serological tests • No deleterious effect of CA and other fingerprint enhancement chemicals on subsequent DNA analysis of STRs (Hochmeister et al., Stein et al., Zamir et al., Frégeau et al.)
! Exceptions ! Use with care - physical developer - shortwave UV light - destaining Deleterious effect on DNA: - Stickyside powder - Stickyside powder + Un-do - prolonged exposure to blood reagents
8. Conclusion • DNA profiles can still be obtained after the use of the majority of fingerprint enhancement techniques • Fingerprint analysis of latent prints can be done BEFORE the DNA analysis of the same subject
Contact informations Zuzana Deščíková Finger, palmprint and trasology department Institute of Forensic sciences (421) 9610-57270 descikova@keupz.minv.sk