1. Target gene selection and isolation: DNA is collected from human fibroblast cells. The gene carrying the interferon code (interferon-beta) is isolated from the DNA.
2. Carrier Selection: Carriers are selected to carry the target gene. Plasmids act as DNA carriers.
3. Local Excision of Plasmid DNA: Specific regions are excised from the carrier plasmid DNA using restriction enzymes.
4. Preparation of recombinant DNA: The interferon gene is ligated to the carrier plasmid DNA by ligase enzymes. As a result, recombinant DNA is produced.
5. Introduction of Recombinant DNA into Host: Recombinant DNA is introduced into cells of host E. coli bacteria. The process of introducing recombinant DNA into bacterial cells is called transformation.
6. Amplification of Recombinant DNA: After the recombinant DNA is introduced into the host cells, the host bacteria are cultivated in culture medium. Within a short period of time, the bacteria multiply in the culture medium to produce thousands of copies. Recombinant DNA is also produced. During this time the bacteria secrete interferon through the culture.
7. Isolation of Interferon: Interferon is isolated from the culture medium. It is then purified by chemical means.
Each yeast cell produces one million (10 lakh) molecules of interferon. 1×105 molecules of interferon are produced inside E. coli.
