Forensic DNA Technology
The US Department of Justice has established CODIS — a national database of DNA profiles from
arrestees, convicted criminals, and crime scene biological evidence — to aid in the identification
of perpetrators and victims. To maintain and augment CODIS, forensic laboratories contribute the DNA
profiles from all DNA evidence to the database as they analyze them. Sometimes DNA samples are
banked until they can be profiled, especially if a crime lab is not available or is overburdened
with other evidence or cases.
To create a DNA profile, the lab will separate and analyze the DNA samples by:
- STR typing - The standard
technique for analyzing samples. CODIS is based on loci tested in STR typing.
- Y-chromosome STR typing - Used in
situations to detect the presence of male DNA in a male-female sample mixture.
- mtDNA sequencing - Especially
useful in cases when the DNA samples are highly degraded or nuclear DNA is difficult to obtain, as in hair or bone samples.
To learn more about the applications of genetic identification in the field of forensics, visit the links below.