Impact of storage conditions and time on DNA yield from ammunition cartridges.
Int J Legal Med
; 137(4): 995-1006, 2023 Jul.
Article
em En
| MEDLINE
| ID: mdl-37237149
ABSTRACT
Recovery of suitable amounts of DNA from ammunition cartridges for short tandem repeat (STR) or mitochondrial (mt) DNA analysis has been a challenge for crime laboratories. The metal composition of cartridge cases and projectiles exposes the DNA to harmful ions that damage and ultimately degrade the DNA such that it cannot be effectively amplified. The current study assessed the impact of time and storage conditions on touch DNA deposited on cartridge components of varying metal content aluminum, nickel, brass, and copper. Elevated humidity levels facilitated greater DNA degradation and loss compared to low humidity (or "dry") conditions, indicating that recovered cartridge component evidence should be stored in a low-humidity environment immediately after collection, preferably with a desiccant. As expected, a relationship was observed between the amount of time elapsed since the cartridge components were handled and the associated DNA yield. Interestingly, while yields dropped considerably in the first 48-96 h post-handling, regardless of the storage conditions, a layering effect was observed that helps maintain a relatively constant level of surface DNA over extended periods of time. An apparent layering effect was also observed on cartridge components following multiple surface depositions, where yields were two times higher than single deposition samples at similar timepoints. Overall, these findings suggest that storage conditions and a layering affect play an important role in the preservation of DNA on ammunition components.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA Mitocondrial
/
Impressões Digitais de DNA
Limite:
Humans
Idioma:
En
Revista:
Int J Legal Med
Assunto da revista:
JURISPRUDENCIA
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Estados Unidos