Patent ID: 8377375

Claim:
A method for determining an effective dose of monochromatic or polychromatic light from one or more light sources to inactivate microorganisms present in a non-transparent biological fluid comprising measuring the effect of the monochromatic or polychromatic light on a dosimetric solution matching the turbidity of the biological fluid at the photoinactivating wavelengths used, the turbidity and absorbance of the biological fluid, the turbidity and the viscosity of the biological fluid, the turbidity and the absorbance and the viscosity of the biological fluid, the absorbance of the biological fluid, or the viscosity and absorbance of the biological fluid, based on a light dose calibration by i) irradiating the dosimetric solution in a layer of an optical path-length sufficiently thin to absorb only a fraction of the incident light at a predetermined defined irradiance for a defined time to apply a defined fluence (light dose) resulting in a change of a measurable physical or chemical magnitude, and ii) by reading out the dose corresponding to the change in the magnitude measured during or after the light irradiation of the dosimetric solution in the light irradiation reactor, wherein step i) is executed before step ii) or vice versa, wherein the biological fluid is inactivated in a flow-through-reactor.