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.
The smallest distances the human eye can resolve is around 0.02 to 0.04 mm, approximately the width of a human hair. A sheet of paper is typically between 0.07 mm and 0.18 mm thick, with ordinary printer paper or copy paper approximately a tenth of a millimetre thick.