Transcript The impact of fingerprint reagent – cyanoacrylate on DNA

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
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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
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Evidence from the
crime scene
Selection of the
right method
Order of expertise
3. Problem
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Persistance of fingerprint / DNA
Factors influencing the fingerprints
Time
Facts
-
Year 2005
3227 cases
3% together with DNA analysis
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Year 2006
2931 cases
2,5% together with DNA analysis
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Year 2007
2178 cases
5% together with DNA analysis
90% of these expertises was delayed app. for
about 3 months
4. Question
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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
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„Superglue“ or
„Krazy glue“
Ethyl-2cyanoacrylate
CA fumes react with
amino acids
Use for smooth,
nonporous surfaces
6. DNA analysis
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Same task as dactyloscopyindividual identification
-
identification of suspects
exoneration of persons wrongly accused of
crime
DVI
establishing of the paternity etc.
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Serological analysis - RFLP –
PCR using STR
Smaller samples, more
sensitive analysis
7. Fingerprints or DNA?
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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
[email protected]