| abstract |
A thin film or layer of white blood cells, such as the contaminating white cells in a platelet concentrate, is irradiated with ultraviolet radiation predominately of a wavelength of 280 to 320 nanometers, and preferably at an intensity of 4 to 20 milliwatts per square cm. to provide a total energy exposure of typically 800 to 20,000 millijoules per square cm. of ultraviolet radiation. The white blood cells so produced substantially lose their capability to set off an immune reaction in an alloimmunized patient. The white blood cells may preferably be placed into such film in a flat, flexible bag made of poly(ethylene-vinyl acetate) plastic, with the flat, flexible bag being stretched in a direction normal to the path of ultraviolet radiation. Novel irradiating devices are also disclosed. |