The sterilization protocol consisted of a 20-minute incubation in bacteriophage (10 4 PFU/mL) suspensions followed by 10 minutes of exposure to UV irradiation. The experiment revealed significant differences in results depending on the bacterial contaminant species. For the E. coli (Gram-negative), the BB itself had a neutral effect, as expected. Only UV irradiation resulted in a 3-log reduction in bacterial titer, while T4 phages alone had a relatively small impact on the number of bacteria. However, combining UV irradiation and BB-stabilized T4 phages reduced bacteria titer to below the methods' detection limits (about 10 CFU/mL). The effect was synergistic and not simply additive.