Photoimmunodetection: a nonradioactive labeling and detection method for DNA.

We describe a simple detection system for DNA based on antibody detection of UV-induced photoproducts. It includes a convenient and inexpensive labeling procedure, which is completed in 5-10 min. The only equipment required is a UV source such as an ordinary transilluminator or a DNA crosslinker. Using a monoclonal antibody specific for thymine dimers, coupled to horseradish peroxidase, we are able to detect subpicogram amounts of UV-irradiated DNA directly, and approximately 10 pg homologues DNA indirectly by hybridization with an irradiated probe.