PCR And Its Use Often times, scientists only have a small amount of DNA to deal with when doing genetic research or studies. In these situations, scientists can do one of several things. One is to just try to work with it anyway, but this is nearly impossible (depending on how much there is). Ther are a couple other processes they can use, or they can use PCR. PCR is one of the more complicated, but reliable ways to do tests on DNA when they only have a small amount to begin with. PCR, or Polymearse Chain Reaction, is the scientific process used by genetic scientists to clone DNA. "A 'rapid diagnostic' technique used in th