In the present age of molecular biology, the study of an organism's genome (its complete DNA) is a central component driving our understanding of biology. When scientists first considered studying genomes they were faced with a problem: how to reproducibly cut a genome's DNA into fragments that were small enough to handle?

As with many of the important discoveries in biology, it was the study of bacteria that yielded this breakthrough. It was discovered that a type of bacterial enzyme was found to have the ability to cut DNA in a test tube. These Restriction Enzymes or restriction endonucleases, so named because they cut double stranded DNA at restricted sites, were discovered as a natural part of the bacterial machinery. In a bacterial cell, restriction enzymes act as a kind of immune system, protecting the cell from the invasion of foreign DNA, as would occur when a virus attempted to infect a bacterial cell. These restriction enzymes provided biologists with a tool to study and manipulate DNA by enabling the generation of consistently sized DNA fragments. They are now used for a wide range of applications, including cloning, Southern hybridization analysis, DNA sequencing and global gene expression analysis.

As there are more than four thousand restriction enzymes reported till date, the systematic compilation of its information becomes all the more important for better implementation of its properties in molecular biology research. Keeping this task in mind, REB, A Restriction Enzyme Database has been developed.

REB is a comprehensive and user friendly database which gives all the information about restriction enzymes, methyltransferases and related proteins. It also provides the user with an efficient tool which gives all the enzymes cutting any DNA sequence. Apart from this REB also gives the information about the commercial availability of enzymes thus proving to be very useful for research as well as commercially.