Recombinant DNA technology involves intentionally modifying the genomes of organisms for practical purposes such as eliminating undesirable traits, combining beneficial traits from different organisms, and creating organisms that synthesize useful products. It utilizes tools such as restriction enzymes, vectors, gene libraries, PCR, gel electrophoresis and probes to isolate, replicate, and insert genes. Applications include genetic mapping, environmental studies, pharmaceuticals, agriculture, and more. However, long-term effects of transgenic manipulations are unknown, and unintended consequences are possible if transgenic organisms interact with natural ecosystems in unforeseen ways.