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.
Asteroids can reach as large as Ceres, which is 940 km (about 583 miles) across. On the other hand, one of the smallest, discovered in 1991 and named 1991 BA, is only about 20 feet (6 meters) across. Nearly all asteroids are irregularly shaped, although a few are nearly spherical, such as Ceres.