Mutagenesis is a process by which the genetic information of an organism is changed in a stable manner, resulting in a mutation. Mutagenesis in the laboratory is an important technique whereby DNA mutations are deliberately engineered to produce mutant genes, proteins, or strains of organism. Various constituents of a gene, such as its control elements and its gene product, may be mutated so that the functioning of a gene or protein can be examined in detail. The mutation may also produce mutant proteins with interesting properties, or enhanced or novel functions that may be of commercial use. Mutants strains may also be produced that have practical application or allow the molecular basis of particular cell function to be investigated.