An important piece of information in the management of a person infected with a chronic virus such as HIV is his/her "viral load" or how many virus particles can be detected. If before PCR, a patient had a viral load of 1.6 x 104 viral particles. What would be the amount of DNA in the sample after the completion of the first PCR cycle?

The Polymerase Chain Reaction (PCR) is a technique widely used in molecular biology to exponentially amplify a specific DNA sample from a small amount of DNA. For this purpose, the PCR technique uses: 1- a DNA polymerase enzyme in order to synthesize new DNA copies and 2- one pair of DNA oligonucleotides (primers) which are complementary to the ends of the target DNA sequence. During each round of PCR, the double-stranded DNA template is unwound and each strand is used to synthesize a new DNA strand, thereby forming two new double-stranded DNA molecules. In consequence, each round of PCR doubles the amount of DNA.