Question

Briefly describe the steps of production of human insulin using rDNA technology.

Hint:

Insulin by rDNA tech = Insert human insulin gene into E. coli → bacteria produce insulin chains → purified → used as Humulin.

Answer 1

Human insulin production by recombinant DNA (rDNA) technology is a major achievement in biotechnology. It is used to treat diabetes mellitus.

Step 1: Identification of Gene.
The gene responsible for insulin production is identified from human DNA. Insulin consists of two polypeptide chains – A and B.

Step 2: Insertion into Plasmid.
The insulin gene is inserted into a plasmid vector (circular DNA from bacteria) using restriction enzymes. This recombinant plasmid is then introduced into E. coli bacteria.

Step 3: Expression in Host.
The bacteria, now genetically engineered, produce insulin polypeptides (A and B chains) as they multiply.

Step 4: Extraction and Purification.
The insulin chains produced by bacteria are extracted, purified, and then chemically combined to form functional human insulin.

Step 5: Use in Medicine.
The recombinant human insulin is marketed as "Humulin" and widely used by diabetic patients.