DNA fingerprinting

                           

                                 DNA Fingerprinting

-        It is way to identify a species or particular trade.

-        A technology used to by scientist to distinguished between individual to same species using samples of the DNA.

-        Discovered by Allex Jeffryesin 1986.

Steps of DNA-Fingerprinting

There are eight steps of DNA-Fingerprinting.

1] Isolation of DNA –

                            DNA must be recovered from cells, only a small amount of blood ski needed to isolate DNA.

2] digestion of DNA by restriction endonuclease -

-        The DNA is cut from fragments by using restriction enzyme.

-        Each restriction enzyme cut`s DNA at a specific base sequence.

-        These sections of that DNA cut out are called restriction enzyme.

-        Reaction mixture are incubated at night 37⁰c.

3] Electrophoretic separation of different fragment –

-        Fragment are separated on the basis of size using a process is called gel electrophoresis.

-        DNA fragment are injected in small wells on the apply electric current along the gel

-        DNA is negative charge then this DNA move to words in positive direction end of the gel.

-        Small DNA fragment fast move than the large fragment.

-        DNA is separated on the basis of size.

4] Transfer DNA on nitrocellulose –

-        The DNA fragments are transfer in nylon sheet by placing the sheets on gel and socking them overnight by the process is called southern blotting.

5] Probe labelling –

-        Adding probe/colored probe in nylon sheet which is complementary in DNA fragment.

6] Hybridization –

-        Labelled probe DNA should be hybridized with the complementary sequence located on nylon membrane for the detection of position of factor membrane washed to remove non-specific binding and the cleaning of the background.

7] Autoradiography –

-        To detect the sequence in genome bound with hybridized, radioactive probe on membrane.

-        The X-ray film after the developed shows multiple number of bonds that look like bar codes and known as DNA fragments.

8] Interpretation of bond pattern –

-        Analysis bond pattern of different individual comparison of position bond.

-        Computer software also available for the analysis of DNA fingerprints.