Applications are growing rapidly in basic research and clinical investigation for the detection with labeled DNA probes of specific DNA Sequences present in cells via in situ hybridization. Currently, it is necessary to radiolabel the DNA probe prior to hybridization, and then perform autoradiography on the specimen that has been probed. Radiolabeling (via such techniques as P32 nick-translation) is costly, time-consuming, and potentially hazardous. In addition, autoradiography often requires long periods of incubation before experimental results can be obtained. A novel, nonradioactive technique for the detection of bound DNA probes is now available from ICN Immunobiologicals, headquartered in Costa Mesa, Calif.
The process, known as the mercury method, is based on the mercuration of the desired DNA probe, followed by the introduction of a trinitrophenyl (Tnp) ligand to the mercury ion. The mercury ion binds to the C5 position of pyrimidine bases. After hybridization of the mercurated probe with the ...