DNA Fingerprinting - Steps Process And Applications who discover
DNA Fingerprinting -and its Applications
It is first discovered by the ALEC JEFFREYS as he stated that In the preceding section 99.9 percent of base sequence among the human is same . assuming human genome as 3×109 b.p (base pair) in the DNA sequence which make every individuals unique in their phenotypic appears fingerprinting is a method for comparing the DNA sequences of any two individuals.
The DNA fingerprints involves identify difference in some specific region in DNA sequence called as repetitive DNA. Because in these sequence ,a small stretch of DNA is repeated many times . these repeated DNA are separated from the bulk genomic DNA as difference peaks during the density gradient centrifugation. The bulk DNA is forms a major peaks during and other small peaks are referred as satellite DNA
Satellites are of two types—micro-satellites and mini satellites, depending upon the base composition, length of segment and the number of repetitive units.
Satellites do not code for proteins, but they form large portion of human genome. These are the sequence which show the high degree of polymorphism and form the basis of DNA fingerprints .Polymorphism is actually a result of mutation. A germ cell mutation (which can pass on to the next generation through sexual reproduction) gives rise to polymorphism in populations.
In the simple terms , an inheritable mutation if observed in higher frequencies in a population is referred as polymorphism.
Polymorphisms arise normally in non-coding sequences because mutations in non-coding sequences do not affect an individual’s reproductive ability. These mutation keep on accumulating generation after generation, and form one of the basis variability /polymorphism .
The satellite DNA as probe that shows very high degree of polymorphism . it is called as VNTR (variable number of tandem repeats) this technique are used earlier , involved southern blot hybridization using the radiolabeled VNTR as probe it included
- Isolation of DNA
- Digestion of DNA by fragments by restriction endonucleases.
- Separation of DNA fragments by electrophoresis.
- Transferring (blotting) of separated DNA , fragments to synthesis membrane .such as introduce nitrocellulose or nylon.
- Hybridization using labelled VNTR probe .
- Hybridized DNA fragments can be detected by autoradiography.
- VNTRs different in size from 0.1 to 20 kb.
- Hence, in the autoradiogram, band of different sizes will be obtained.
- These bands are characteristic for an individual. They are different in each individual, except identical twins.
Applications of DNA Fingerprinting
- Physically connect a piece of evidence to a person or rule out of someone as a suspects .
- It also show who your parents , siblings, and other relative etc.
- To Identify a dead body that is too old or damaged to to be recognizable
- It is used match of tissue of organ donor with those of people who need transplants .
- Identify of disease that are passed down through your family
- It also help to find cure of those disease ,called hereditary condition
- It can be used for studying genetic diversity in a population and evolution.
Q.In which of the following scientist who discovered DNA Fingerprints ?
A. Albert Einstein
B. Whittaker
C. Sutton Bovery
D. Dr Alec Jaffrey
Answer: Dr Alec Jaffrey
Q.In which of the following Year DNA Fingerprint was discovered?
A. 1984
B. 1999
C. 2002
D. 2003
Answer: 1984
Q.In which of the following sate is correct about the DNA Fingerprints
A. Its use to control the brain
B. Its use to describe land square
C. Its use to detect length of speed
D. Its use to find cure of those disease ,called hereditary condition
Answer: Its use to find cure of those disease ,called hereditary condition