NEBcutter®, a computer program for restriction enzyme site mapping is available on the NEB web site in the sidebar under ""Favorite Tools"". The program accepts sequences retrieved from a local file or GenBank. It aslo accepts an input sequence pasted into a designated field. When presented with a sequence, NEBcutter will find the largest open reading frames within the sequence and indicate those restriciton enzymes that could be used to excise the gene. It also locates the positions of all restriction enzymes that cut only once within the sequence chosen. NEBcutter is also fully aware of the information on the methylation sensitivity of restriction enzymes and alerts a user to overlapping methylation by dam, dcm, etc.