The gene for human insulin is inserted into the gap in the plasmid. ... This cell then divides rapidly and starts making insulin. To create large amounts of the cells, the genetically modified bacteria or yeast are grown in large fermentation vessels that contain all the nutrients they need.
Firstly we prepare two DNA sequences corresponding to chain A and B of human insulin. It is introduced in a plasmid of Escherichia coli to produce insulin chains . Chain A and B are produced separately, extracted and combined by creating disulfide bonds to form human insulin or Humulin.
