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 size visible through the naked eye is generally about 0.1 mm (100 Âµm) and through a light microscope is about 0.2 Âµm (200 nm); anything less than 1 Âµm cannot be seen clearly without an electron microscope. However, living organisms cannot be observed using an electron microscope.