Answer:
Polymerase chain reaction (PCR)
Explanation:
Polymerase chain reaction (PCR) is a method by which a target DNA fragment is amplified to produce millions of copies. In PCR, the Taq polymerase enzyme uses nucleotides and primers to replicate a small DNA segment in vitro and produces two DNA molecules. The newly formed DNA molecules are denatured by heating to facilitate their replication to produce four double-stranded DNA molecules. In this way, the number of DNA molecules is doubled in each cycle. Therefore, the small amount of DNA obtained from the minuscule spot of blood on a murder suspect’s shirt can be amplified using PCR.