Nucleic acid photobiotin

Forster, A.C., Mclnnes, J.L., Skingle, D.C., and Symons, R.H. (1985) Non-radioactive hybridization probes prepared by the chemical labeling of DNA and RNA with a novel reagent, photobiotin. Nucleic Acid Res. 13, 745-761. 

Nucleic acids can also be biotinylated by nonenzymatic methods with photobiotin, a photoactivatable biotin analog (6), which can be commercially obtained from BRL, Sigma, and other commercial sources I have not compared the suitability of this method of biotin incorporation with that reported here, but expect that the method would be fully acceptable FMC (Rockland, ME) markets an alternate nonradioactive sequence detection kit known as Chemiprobe. The basis of this system is a chemical modification of cytosine residues m the probe DNA. After hybridization, the probe is detected by means of a monoclonal antibody that specifically recognizes the sulfonated DNA. Detection of the bound monoclonal antibody is achieved by means of an alkaline phosphatase-conjugated second antibody. 

Photohaptens photobiotin or photodigoxigenin can be introduced by simple methods photohaptens react with many different molecules and nucleic acid preparation should be very pure detectability somewhat inferior... 

Psoralens (furocoumarins used by some plants in defence from insects and fungi) photoreact with ds DNA to form interstrand crosslinks in the presence of near-UV light by two steps intercalation in the dark and formation of monoadducts or interstrand crosslinks (Song and Tapley, 1979). This reaction has the advantage that psoralen binds, in contrast to photobiotin, only to nucleic acid. 

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