DNA profiling

DNA profiling is a technique used to identify individuals by the observing characteristic variations within their DNA.

How to detect variation?

DNA profiling is based on the principle that there are variations that exist between individuals between genes, which can be used to help identify an individual. These variations include:

  • Short tandem repeats: Small repeat sequences that occur one after each other.
  • Variable number tandem repeats.

How DNA profiling works?

Once  DNA strands have been obtained they are treated with restriction enzymes that cuts at some point of the gene (which will cut at different lengths depending on the nature of the DNA sequence). This produces fragments of different lengths known as restriction fragment length polymorphisms. These fragments are separated out on gel electrophoresis  and treated with a probe to identify specific bands.

What is DNA profiling used for?

  • Establishing parentage.
  • Establishing family relationships.
  • Analyzing criminal evidence such as semen or blood.
  • Establishing genetic variation in threatened species.
  • Establishing evolutionary relationships.

See also