What are DNA probes?



DNA probes are small segments of DNA which help to detect the presence of a gene of a long DNA sequence, in a biological systems. These DNA probes are prepared for commercial purposes and are believed to be the most sophisticated and sensitive means to identify genes or specific DNA sequences. DNA probes provide commercial avenues for diagnosis of infection diseases, identification of food contaminants for isolation of genes and in other microbiological tests.

It is believed that, these DNA probe assays for variety of purposes will be cleaner, simpler, faster and cheaper than the traditional microbiological tests and are also expected to be hundred fold more sensitive.

The production of DNA probes can be done by any of the following methods. Such as (a) using a template DNA with the help of purified biological enzymes (b) DNA probe of specific sequence can also be obtained by using automated DNA synthesizers (c) DNA probe can also be included in viral DNA and may even multiply in bacteria, thus by this way many copies of DNA probe can be obtained.

However, the DNA probe assay consists of the following steps. Sample to be tested is treated with detergents and enzymes to remove non DNA components. Then DNA is denatured by low PH. Single stranded DNA binds on filters and is exposed to excess of DNA probes but only one of which will hybridize. At the same time unbound DNA is detected by a variety of available methods using florescence and dye etc.