1. Southern Blotting technique: This technique is used for the analysis of DNA segments. This was developed by E.M. Southern (1975) and hence named so. In this technique, the DNA segments are transferred on a nitrocellulose filter. These are then identified by hybridization with the DNA probes. 

2. DNA Fingerprinting: DNA Finger Printing was discovered by Alec Jeffreys and coworkers (1985). In this method DNA of a specific person is cut into small segments and is separated in the form of bands by electrophoresis. The identity of a person can be established by the specific base sequence found in the DNA of the person. This technique is used in resolving disputed paternity of any child and in detecting genetic diseases prior to the birth of a child. It is also used in the identification of criminals (Murderers and Rapists etc.) 

3. Polymerase Chain Reaction (PCR): Polymerase Chain Reaction was discovered by Mullis (1989). It is a powerful technique by which millions of copies of one DNA molecule can be obtained in a very short time without involving vectors for replication of DNA. This is performed in DNA thermal cycler. By repeating this cycle 20 – 30 times lacs of copies of DNA are obtained. 

4. Nomenclature of Restriction Enzymes: 

• The first alphabet of the name of enzyme represents the name of the genus from which it has been isolated. It is written in capital letters.
• The two alphabets after this represent the species of the genus. These are written in small letters. Note: All the three letters are written in italics. Example: E co = Escherichia coli.
• The fourth alphabet (word) represents the strain of the species from which the enzyme has been isolated. Example Eco R = R strain of E.coli.
• If more than one restriction enzymes are derived from the same organism (same strain), these are indicated by Roman numbers. Example: Eco RI, First restriction enzyme from R strain of E.coli. Eco RII, Second restriction enzyme from R strain of E.coli. 

5. Features of Vectors: 

• It can be inserted easily into the host cell and can be isolated easily.  It should freely self replicate in the host cell.
• The vector must posses Restriction sites so that restriction enzyme can cut the DNA at that site so that the desired DNA fragment can be incorporated easily.
• It should have one marker gene or marker site which can help in the selection of recombinants cells. 
• Transformation should be easy and perfect. 
• For expression of desired foreign DNA, the vector should essentially possess components such as a promoter, operator regulating sites.