Molecular Basis of Inheritance Test - 12

Sir Alec John Jeffreys, CH FRS (born 9 January 1950 in Oxford, Oxfordshire, England) is a British geneticist, who developed techniques for DNA fingerprinting and DNA profiling which are now used worldwide in forensic science to assist police detective work and to resolve paternity and immigration disputes.

He is a professor of genetics at the University of Leicester, and he became an honorary freeman of the City of Leicester on 26 November 1992.

In 1994, he was knighted for services to genetics

The main types of Genetic (DNA) fingerprinting methods in use at this time are:

• Restriction fragment length polymorphism (RFLP) analyzes the length of the strands of the DNA molecules with repeating base pair patterns. The drawback with this system is that it requires a considerable amount of DNA in order to be used.
• The polymerase chain reaction (PCR) was developed by Karry Mullis of the Cetus Corporation in 1983 for use in research laboratories for establishing hereditary authentication. The drawback was that it was not as discriminating as the RFLP.
• Amplified fragment length polymorphism (AmpFLP) came into vogue in the 90's and is still popular in the smaller countries involved in the process of DNA fingerprinting.
• The short tandem repeat (STR) methodology for extracting DNA is the system most widely used form of DNA fingerprinting.

Satellite DNA consists of very large arrays of tandemly repeating, non-coding DNA. Satellite DNA is the main component of functional centromeres, and form the main structural constituent of heterochromatin.

It is a useful tool in forensic science as the density of DNA differs in from each other. It is used to identify the individuals form the other.

The application of the power of molecular genetics to the problems of human disease plays an important role in many of the research programs in the Department of Biology.

Several complementary approaches are used by our research groups. The power of genomic analysis is used to identify, isolate and characterize genes which cause and contribute to the etiology of human diseases.

Human disease is also studied through the functional analysis of key genes: low density lipoprotein receptors in atherosclerosis and stroke; a broad spectrum of tumor suppressors and oncogenes in cancer, genes directly leading to the disease etiology in neuromuscular disorders such as Alzheimer's, Huntington's disease, and muscular dystrophies.

Gel electrophoresis is used to separate macromolecules like DNA, RNA and proteins. DNA fragments are separated according to their size and proteins can be separated according to their size and their charge (different proteins have different charges) to study the genome of individual organism.

DNA fingerprinting is a method used to identify an individual from a sample of DNA by looking at unique patterns in their DNA.

DNA is extracted from a biological sample. STR analysis is incredibly sensitive so it only needs a tiny amount of someone’s DNA to produce an accurate result. As a result the DNA can be extracted from a wider range of biological samples, including blood, saliva and hair and body secretion etc.

DNA paternity testing is the most accurate form of paternity testing possible. If DNA patterns between the child and the alleged father do not match on two or more DNA probes, then the alleged father can be totally ruled out. If the DNA patterns between mother, child, and the alleged father match on every DNA probe, the likelihood of paternity is 99.9 percent.

Polymerase chain reaction (PCR) is a wonderful technology for amplifying DNA. It allows you to take a specific region of DNA on the chromosome and through the use of primers, copy back and forth, only a particular desired segment, making two, then four, then eight, then sixteen, and so on, up to millions of copies.

It is possible to start from the DNA segment of a single cell and produce enough of it for use in DNA typing or fingerprinting.

In finger printing the nylon membrane was incubated with radioactive probes. DNA Probes are small fragments of minisatellite DNA tagged with radioactive phosphorous. The probes only attach to the pieces of DNA that they are complementary to – in this case they attach to the minisatellites in the genome. Radioactive isotopes can be easily identified using scanner.

Polymerase chain reaction (PCR) is a technique used in molecular biology to amplify a single copy or a few copies of a segment of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence.

This increae the sensitivity of the technique.