Enlist the steps in DNA Finger Printing Giving its applications.

Isolation of DNA:- The DNA can be isolated even from the small amount of tissue like blood, hair roots, skin etc. 

Restriction digestion:- 

1. the isolated DNA is treated with restriction enzymes which cut the DNA at specific sites to form small fragments of variable lengths. 
2. Variations in the length of restriction fragments are known as restriction fragment length polymorphism. 

Gel electrophoresis:-

1.  the dna samples are loaded on agarose gel and electrophoresis is carried out. 
2. Negatively charges DNA fragments move to the positive pole. 
3. Separation of fragments depends on their length and it results in formation of bands. 
4. Thus, dna is then denatured in sadna by alkali treatment. 

Southern blotting:-

1.  the separated dna membrane or a nitrocellulose membrane. 
2. It is obtained from organisms or prepared by cDNA preparation method. 
3. The dna probe is labelled with radioactive isotopes. 

Hybridization:- 

1. in this process, proble is added to the nitrocellulose membrane containing DNA fragments. 
2. The single stranded dna probe pairs with the complementary base sequence of the dna strand. 
3. As a result dna - dna hybrids are formed on the nitrocellulose membrane. Unbound single stranded dna probe fragments are washed off.

Photography:- the nitrocellulose membrane is then kept in contact with X - Ray film. Dna bands, due to radioactive probe, give photographic image on x-ray film. This is autoradiography.