DNA fingerprinting, also known as DNA profiling, is a technique used to identify individuals based on their unique DNA patterns. Here’s a simple explanation:
- Unique
DNA Patterns: Every person (except identical twins) has a unique DNA
sequence. DNA fingerprinting takes advantage of these unique patterns.
- Focus
on Repetitive DNA: The technique often focuses on regions of DNA that
vary greatly among individuals, such as satellite DNA, which includes
short tandem repeats (STRs).
- Process:
DNA Isolation: Extract DNA from the sample cells (such as blood, saliva, or hair).
DNA Digestion: Use restriction enzymes to cut the DNA at specific sequences, creating fragments of varying lengths.
Fragment Separation: Separate the DNA fragments based on size using gel electrophoresis, which involves applying an electric field to move the fragments through a gel matrix.
Fragment Transfer: Transfer (blot) the separated DNA fragments from the gel onto a synthetic membrane, such as nylon.
Hybridization: Expose the membrane to labelled probes that bind to specific Variable Number Tandem Repeat (VNTR) sequences in the DNA fragments.
Detection and Analysis: Visualize the hybridized fragments using autoradiography or another imaging technique to produce a pattern that can be analyzed and compared.
- Applications:
- Forensic
Science: Identifying suspects or victims in criminal investigations.
- Paternity
Testing: Determining biological relationships.
- Personal
Identification: Verifying identities in security and legal contexts.
- Genetic
Research: Studying genetic diversity and inherited traits.
DNA fingerprinting is powerful because it can match a DNA
sample to a specific person with high accuracy due to the unique nature of an
individual's DNA.