DNA Fingerprinting and Uses
- DNA Fingerprinting is a pattern of bands made up of specific fragments from an individual’s DNA
- Banding patterns from two individuals can be compared if they are related
- Banding patterns from two species can be compared to see if they are similar
- Technology is used in forensic science and in medical research to:
- Convict criminals from blood samples and tissue samples
- Determining the origin of diseases
- The Method for making a DNA Fingerprint is called (RFLP) Restriction Fragment Length Polymorphism Analysis
- The DNA sample is first cut into many fragments by restriction enzymes
- The DNA fragments are separated according to size by Gel Electrophoresis
- Radioactive probes then bind to DNA fragments that have been selected for comparison
- Photographic film allows visualization of the radioactive probes, producing the DNA Fingerprint
- Every person, except identical twins, has a unique sequence of DNA in their cells
- The sections that vary the most between individuals are the non-coding sectors of DNA
- In non-coding sections of DNA, there meaningless patterns of meaningless code (GGAT)
- There is less than a million in one chance that 2 people have the exact same repeating pattern in 5 specific non-coding portions of DNA
- The FBI uses a comparison of 12 sites. The probability of 2 people having the exact same repeating pattern at 12 sites is 1/60,000,000,000 (60 Billion)