Polymerase chain reaction (PCR) is a laboratory technique used to amplify DNA sequences. The method involves using short DNA sequences called primers to select the portion of the genome to be amplified.olymerase chain reaction (PCR) is a laboratory technique used to amplify DNA sequences. The method involves using short DNA sequences called primers to select the portion of the genome to be amplified.
The smallest possible size for anything in the universe is the Planck Length, which is 1.6 x10-35 m across.
Distances smaller than that are similarly described in reference to the equine body with terms such as a neck, and a head, a short head or nose, the smallest possible named advantage by which a horse can win. In the United Kingdom and Ireland a margin of more than 30 lengths is described as a distance.