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.
When f(x), L, x, and a are real numbers, the distance between two numbers is the absolute value of the difference of the two. Thus, when we say f(x) is close to L we mean | f ( x ) â L | {\displaystyle |f(x)-L|} is small. When we say that x and a are close, we mean that | x â a | {\displaystyle |x-a|} is small.