How are the following used in biotechnology?
(i) Plasmid DNA
(ii) Recognition sequence
(iii) Gel electrophoresis
Answers
a. Plasmid DNA : The construction of the first recombinant DNA molecule emerged from the possibility of linking a gene encoding antibiotic resistance with a native plasmid of Salmonella typhimurium. Stannely Cohen and Herbert Boyer accomplished this in 1972 by isolating the antibiotic resistance gene by cutting out a piece of DNA from a plasmid that was responsible for conferring antibiotic resistance.
b. Recognition sequence : The first restriction endonuclease HindII, whose functioning depended on a specific DNA nucleotide sequence, was isolated and characterized five years late.This specific base sequence is knows as the recognition sequence for HindII.
c. Gel electrophoresis : The cutting of DNA by restriction endonuclease results in the fragments of DNA. These fragments can be separated by a technique knows as gel electrophoresis.
Plasmid DNA:
Plasmid DNA has some basic features which are used in the biotechnology. It has feature of multiple site of the cloning where gene can be added. It has also a location where the replication starts. This is a place where the replication of the DNA starts. A plasmid also has a selective marker, which is required to maintain plasmid of cell.
Recognition Sequence:
Restriction enzyme is a protein which is produced by the bacteria. Each of the restriction enzyme has four bases like adenine, cytosine, guanine and thymine. This region is known as recognition sequence.
Gel Electrophoresis:
Gel electrophoresis process helps to separate the DNA, RNA and protein in the biotechnology. DNA and protein is separated according their size and the charges.