Rapid complementation method for classifying excision repair-defective xeroderma pigmentosum cell strains.

A rapid method has been developed that permits demonstration of complementation between different cell strains from ultraviolet-sensitive xeroderma pigmentosum patients. Combining polyethylene glycol-mediated cell fusion with low doses of ultraviolet light to eliminate unfused sensitive cells, the method permits assignment of cell strains to complementation groups by visual inspection, avoiding use of laborious methods involving autoradiography. This method can be augmented by measuring DNA repair synthesis, which shows large quantitative differences between fusions that result in complementation and those that do not.