· Cut out the insulin gene from the DNA of a human cell using an enzyme.
· Remove a ring of DNA from a bacterium and open it up using the same enzyme.
· Insert the insulin gene into the plasmid using another enzyme.
· Enable a bacterium to take up the altered DNA.
· Put the bacterium in a fermenter, and it multiplies many times.
· Each new bacterium contains the insulin gene.
· The bacteria produce insulin which can be extracted.