Abstract
The cytotoxic effect of the photosensitizer Methylene Blue activated with long wavelength laser radiation has been investigated using mice with solid Ehrlich carcinomas. A krypton laser was used as a light source emitting laser radiation at 647 nm and 676 nm. The red spectral range is important for photochemotherapy because it is easily transmitted through tissue. A significant tumor reduction, including complete tumor destruction, has been achieved.