Topic 5 Flashcards
plays a vital role in forensic science throughexonerating the innocent and convicting the guilty.
Deoxyribonucleic acid (DNA)
In cases where a suspect has not yet been identified, biological evidence from the crime scene can be analyzed and compared to offender profiles in DNA databasesto help identify the perpetrator.
DNA in Forensic Investigation
was first recognized as having application to forensic science by the British molecule biologist Alec Jeffreys.
During the mid 1980s DNA analysis
is stable – it can be isolated from material that is months or even years old.
DNA
can be replicated in the laboratory – from a very small amount of initial material through the process of PCR (POLYMERASE CHAIN REACTION).
DNA
shows greater variability from one individual to the next.
DNA
is functionally the hereditary material that contains the genetic information necessary for the duplication of cells and for the production of proteins. Chemically, it is an acid, is phosphorous rich, it contains a deoxyribose sugar, it contains the four bases show the unique property of pair wise equivalency. It is a double helix composed of two complimentary strands.
DNA
is a chemical substance found in all cells whose composition have been passed on from parents to their children. All cells in the body have the same DNA composition slept individual egg and sperm cells.
DNA – de – oxy – ri – bo – nucleic acid
that can be submitted for DNA analysis:
Blood and bloodstain
Semen and seminal stain
Hairs and follicles or root
Saliva or buccal swabs
Bones and organs
Tissues and cells
Biological Evidences
in forensic casework was first performed using this technique.
DNA analysis
is done by first carefully extracting the DNA from the evidentiary samples. The DNA is then analyzed to give a particular pattern. The patterns are compared with that of a known individual to determine a match.
DNA Typing
