1. mRNA of the TPA gene has been isolated from human cells.
2. cDNA is made from mRNA.
3. Recombinant DNA is created by combining cDNA with plasmids.
4. Recombinant DNA is introduced into host cells.
5. Hosts with recombinant DNA are cultured in culture medium and thousands of copies are made.
6. Medicines are prepared by isolating the TPA protein from the host.
7. Pushing TPA injection into the blood vessel of a heart attack or stroke patient dissolves the blood block and the patient recovers.