MY GRAND DAUGHTER IS WORKING WITH PCR
In 1985, Kary Mullis invented the process known as polymerase chain reaction (PCR), in which a small amount of DNA can be copied in large quantities over a short period of time. By applying heat, the DNA molecule's two strands are separated. Then DNA polymerase adds nucleotides to each strand. And new DNA chains are formed. Then the process is repeated. (DNA replication is a precise process. When a cell is ready to turn into two new cells its DNA unwinds. DNA is a ladder with two sides. Before a cell reproduces the two sides of the ladder split into two strands. Each half of the ladder becomes an independent component. Then an enzyme called DNA Polymerase performs a magical feat. It causes nucleotides, one by one, to line up and form a second strand. It's like---the polymerase makes each nucleotide know when it's their turn to attach to it's opposite. (A's attaches to C's; G's line up opposite T's....