DNA profiling

Today I am going to share information about DNA profiling and it's importance.

What is DNA

Deoxyribonucleic acid is the hereditary material in humans and almost all other organisms. DNA carry genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses. There are three types of DNA. These are terms A-form, B-form,and Z-form DNA.

What is DNA profiling

DNA profiling is process of determining an individual's DNA characteristics. It is use to get profile (DNA pattern) from a person.

Human DNA consists of 3 billion bases (ATCG). More than 99% of those bases are the same in all people. However, specific regions vary highly between people. These regions are called polymorphic. These different region inherit by our parents is known as polymorphisms. These unique region helps to get DNA profile.

History of DNA profiling

DNA profiling first started out in the 1980s.

The first patent covering the direct use of DNA variation for forensics was filed by Dr. Jeffrey Glassberg in 1983. In the UK, Geneticist Sir Alec Jeffreys independently developed a DNA profiling process in beginning in late 1984, while working in the Department of Genetics at the University of Leicester.

In India DNA fingerprinting was started by Dr. VK Kashyap and Dr. Lalji Singh. Dr.Singh was popularly known as the "Father of Indian DNA fingerprinting".

DNA profiling methods

DNA EXTRACTION 

DNA need to extract from cell and purified.

The cell and nuclear membranes need to be broken up to allow the DNA to be free in solution. Once the DNA is free, it can be separated from all other cellular components. After the DNA has been separated in solution, the remaining cellular debris can then be removed from the solution and discarded, leaving only DNA. There many methods to extract DNA. These are Organic extraction,Chelex extraction and solid phase extraction.

RFLP analysis

DNA is collected from cells and cut into small pieces using a restriction enzyme (a restriction digest).

Polymerase chain reaction (PCR) analysis

PCR is a method widely used to rapidly make millions to billions of copies of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it to a large enough amount to study in detail.

STR analysis

Short tandem repeats are regions of non-coding DNA that contain repeats of the same nucleotide sequence. For example, ATCGATCGATCGATCG is an STR where the nucleotide sequence ATCG is repeated four times.

The variable (polymorphic) nature of the STR regions that are analyzed for forensic testing intensifies the discrimination between one DNA profile and another.

Application of DNA profiling

• It is used for parentage testing, to establish immigration eligibility, and in genealogical and medical research.
• Identification of blood relatives.
• It is used to detect maternal cell contamination.
• DNA profiling also enhances the criminal system's accuracy.