The product of the Polymerase Chain Reaction (PCR) may be generically suitable for four types of investigations: Discovery PCR, Analytical PCR, Modification by PCR, and Synthetic PCR. Despite the potential problem of contamination with extraneous DNA, PCR is relatively simple and inexpensive, and thereby offers opportunities for laboratories from smaller or developing countries to invest limited resources in competitive global research and development, or in applications of economic and social value in health, agriculture and other sectors.