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 least count is the value of the smallest scale division of the measurement instrument. Example: a ruler with marks 1 millimeter apart has a least count of 1 millimeter The least count of an instrument is the size of the smallest scale division on the instrument. 1  The smaller the least count the more precise the instrument is said to be. For example a metric ruler which has millimeter marks has a least count of 1 mm or 0.1 cm. and when properly used it can make more precise measurements than one with centimeter marks. 203.4 cm: least count of ruler was 1 cm, tenth of centimeter was estimated.