Abstract: Methods for pathogen reduction in donor blood are performed by exposure of blood to UVC irradiation. Unwanted wavelengths of light, mostly in the infrared spectra, may be precluded from reaching blood by providing a layer of IR-absorbing fluid positioned between blood and the source of UV irradiation, whereby minimizing energy absorption and heating of blood. Some embodiments further disclose utilizing the same IR-absorbing fluid to actively cool blood by flowing the IR-absorbing fluid along the blood flow path.

Abstract: Disclosed are methods for pathogen reduction in blood by illuminating with UV light while taking steps for preservation of blood components and reducing oxidative damage from reactive oxygen species generated during UV light exposure. Fresh whole donor blood or products derived therefrom may be submitted to UV light treatment while in a low oxygenation state defined by a partial oxygen pressure below a normal level. Such low oxygenation state occurs naturally shortly after blood collection or may be induced by exposure to low-oxygen environment, reducing temperature or by other disclosed steps.