Primers are small DNA sequences that are designed to start DNA replication in a laboratory technique called polymerase chain reaction, or PCR, to amplify certain segments of DNA. Forward and reverse primers differ in the... More »

Forward biasing is when voltage is applied across a P-N junction in the forward direction, according to About.com. A reverse bias does just as the name suggests, reversing the flow of the current through the diode. More »

Typically, when a car will move in reverse, but not in forward, the transmission is having issues. The reverse clutch in the transmission may have become dislodged. More »

PCR, or polymerase chain reaction, uses repeating cycles of heating and cooling to replicate strands of DNA from a sample. PCR can amplify and copy a single gene from a sample multiple times. More »

The three-step PCR process, or polymerase chain reaction, is used to amplify or copy DNA sequences. First, the two strands of DNA separate. Second, RNA primers anneal or attach to the DNA. Third, heat stable polymerase c... More »

A PCR machine, also known as a thermal cycler, is a DNA amplifier that regulates temperature and amplifies segments of DNA via the polymerase chain reaction. As Wikipedia points out, PCR machines are also sometimes used ... More »

A polymerase chain reaction, or PCR, consists of three steps: DNA denaturation, primer annealing and extension. These steps are repeated between 20 and 35 times to synthesize the correct quantity of the DNA of interest. ... More »