The use of recombinant DNA technology

in the synthesis of human insulin by bacteria

• mRNA coding for insulin/isolate gene for human insulin;
• from beta cells of islets of Langerhans/pancreas;
• reference to reverse transcriptase;
• to cDNA;
• reference PCR/DNA polymerase/double strand;
• reference sticky ends;
• use of vector/virus/plasmid;
• reference endonuclease/restriction enzymes;
• to cut plasmid;
• reference DNA ligase to join DNA;
• inserted into suitable host cell/E.coli/bacteria;
• reference method of insertion;
• identification of modified bacteria;
• reference growth/culture of engineered bacteria in fermenters

The gene coding for human insulin

Can be obtained and inserted into a plasmid vector.

• obtain mRNA from β cells (of islets of Langerhans of pancreas) ;
• reverse transcriptase ;
• make (single-stranded) cDNA ;
• DNA polymerase used to make cDNA double stranded ;
• sticky ends created ;
• (obtain) plasmids ;
• cut with restriction, endonuclease/ enzyme ; A named e.g. EcoR1
• ref. complementary sticky ends ;
• cDNA / insulin gene, mixed with plasmid ;
• DNA ligase ;
• seals nicks in sugar-phosphate backbone ;

The advantages of treating diabetic

People with human insulin produced by gene technology.

• it is identical to human insulin ;
• (more) rapid response ;
• no/ fewer, immune response/ side effects/allergic reactions ;
• ref. to ethical/ moral/ religious, issues ;
• cheaper to produce in large volume/ unlimited availability ;
• less risk of, transmitting disease/infection ;
• good for people who have developed tolerance to animal insulin ;