BRAINCAKEDNA Profiles
A DNA profile is a pattern, usually shown as a series of bands or peaks, that represents the number of repeats a person has at several satellite DNA loci. Because the number of repeats varies so much between people, everyone except identical twins has a different DNA profile.
Modern DNA profiles use short tandem repeats (STRs). At each locus a person has two alleles, one from each parent, so each locus gives one or two bands. In the UK, profiles are based on 16 STR loci plus a marker that shows whether the DNA is from a male or a female.
Producing a DNA profile (an overview):
1. DNA is extracted from a sample such as blood, saliva, hair roots or skin cells.
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Key terms in this lesson
- short tandem repeat
- A short DNA sequence of a few bases repeated many times in a row at a particular locus, with the number of repeats varying between individuals.
More in Gene Sequencing
- DNA Sequencing
- Using DNA Sequencing
- Using DNA Sequencing to Manage Disease
- Introns and Satellite DNA
- Gel Electrophoresis
- Southern Blotting and Gene Probes
- Forensic Science
- Paternity Testing
All 12 lessons in Gene Sequencing · All Edexcel A-level Biology topics