Of late, genetic engineering or recombinant DNA technology has been emerged as a very potential filed
in molecular biotechnology. DNA isolation and characterization are the requisites of many fundamental molecular
researches and thus have become an integrated part in the study of both basic and applied molecular biology. In the
basic fields, researches are carried out to know the functions of different genes, their expression patterns etc. which in
turn, is making pace for the advanced and applied researches. In the applied fields, molecular techniques have been
adopted to produce thousands of commercial products including different agricultural and pharmaceutical products that
are being served to fulfill regular consumer requirements. Therefore, recombinant DNA technology is playing very
important role in both basic and applied researches. In this chapter, basic and fundamental techniques as well as recent
advanced techniques used in molecular biotechnology have been described along with some diagrammatic illustrations.
The process for isolation and characterization of a gene has been described sequentially and step-wise to make it easily
understandable. In addition, the entire process for cloning a gene in different circumstances has been presented in
schematic-form in the last part of the chapter for a comprehensive review.
Keywords: recombinant DNA, restriction nuclease, polymerase chain reaction, DNA sequencing, vector, nucleotide probe
