Wavelength Dependence for the Induction of Bacteriophage Lambda by Antitumor Agent Gilvocarcin V

The wavelength dependence for the induction of a lambda‐lacZ fusion phage of E. coli by photo‐activated gilvocarcin V was determined using a spot test or a quantitative assay for the lacZ gene product. Suspensions of bacteria and chemical were exposed to radiation of different wavelengths in the region 313‐546 nm, using a double grating monochromator. The prophage induction profiles generated were similar to the absorption spectrum of gilvocarcin V in this region, with a peak near 400 nm. The radiation fluence and chemical concentration required for threshold levels of prophage induction exhibited a nearly reciprocal relationship. These results have implications for the therapeutic use of gilvocarcins as antitumor agents.