Uses of Genetic Fingerprinting (AQA A Level Biology): Revision Note

Uses of genetic fingerprinting

Forensic science

• Crime scene investigations

  • DNA profiling has been used by forensic scientists to identify suspects of crimes

    • Samples of body cells or fluids (e.g. blood, saliva, hair, semen) are taken from the crime scene or victim's body (e.g. victims of sexual abuse)

    • DNA is removed and profiled

    • The profile is compared to samples from the suspect (or criminal DNA database), the victim and people with no connection to the crime (control samples)

    • Care must be taken to avoid contamination of the samples

  • DNA profiling can also be used in forensics to identify bodies or body parts that are unidentifiable (e.g. too badly decomposed or parts remaining after a bomb blast)

• Genetic fingerprinting is used in forensic science because each person (except identical twins) has a unique DNA profile, particularly in their VNTR regions

  • If the DNA pattern from a suspect matches the DNA found at the scene, it provides strong evidence that they were present

  • Conversely, a mismatch can exclude someone from suspicion

Medical diagnosis

• Detecting genetic disorders

  • DNA fingerprinting can identify disease-causing alleles or inherited conditions

  • E.g. Identifying alleles linked to Huntington’s disease, cystic fibrosis, or BRCA1/BRCA2 in breast cancer

• Carrier screening

  • This process helps determine if a person is a carrier for a recessive genetic condition

• Tissue typing

  • DNA fingerprinting is used before organ transplantation to check compatibility

• Genetic fingerprinting is used because some diseases (e.g. Huntington’s, cystic fibrosis) are caused by specific mutations or patterns in the genome

  • By comparing a patient’s DNA to that of known affected individuals, scientists can detect the presence or absence of disease-causing alleles

  • It can also be used to predict disease risk or to guide treatment plans based on genetic profiles

Animal and plant breeding

• Genetic fingerprinting can be used to:

  • ensure that selective breeding programs are effective

  • confirm parentage or pedigree in livestock and crops

  • maintain genetic diversity and reduce inbreeding

• Genetic fingerprinting is used because breeders can confirm that offspring have inherited the correct genetic traits (e.g. high milk yield, disease resistance)

• It helps identify unrelated individuals to maintain genetic diversity, which is important for the long-term health and productivity of a population