Mutations are sudden heritable changes seen in organisms. Evolution is brought about through mutations. In the present experiment induction of auxptrophic mutants in E.coli have been brought about using two mutagens, viz., N-methyl –N-nitro-N-nitrosoguanidine and 5-Bromouracil.The number of colonies obtained using Nitrosoguanine (NG) were 35(average) and Bromouracil(BU) were 30(average). The results validate the methodology adopted and prove that the mutagens were effective.