Methods are disclosed for sterilizing tissue to reduce the level of one or
more active biological contaminants or pathogens therein, such as viruses, bacteria,
(including inter- and intracellular bacteria, such as mycoplasmas, ureaplasmas,
nanobacteria, chlamydia, rickettsias), yeasts, molds, fungi, spores, prions
or similar agents responsible, alone or in combination, for TSEs and/or single
or multicellular parasites. The methods involve sterilizing one or more tissues
with irradiation.