Recombinant DNA, often shortened to rDNA, is an artificially made DNA strand that is formed by the combination of two or more gene sequences from different species. Recombinant DNA is engineered specifically for a purpose. For example, recombinant DNA can be used to change the genetic makeup of a bacterial cell in order to make it produce insulin. Recombinant genes, and the recombinant proteins they produce, have become widely used in medicine. They offer a novel method of managing some health conditions, such as the use of recombinant insulin in diabetes.