We exposed T4 phages to UV dose, causing complete (> 5 log, i.e., below the methods' detection limit <25 PFU/mL) deactivation of virions (1 minute, ~360 mJ/m 2 ). All eight judiciously chosen food dyes (tartrazine (TR), quinoline yellow (QY), sunset yellow FCF (SY), Ponceau 4R (PC), Allura red (AR), azorubine (AZ), brilliant blue FCF (BB) and indigo carmine (IC) provided nearly perfect protection to bacteriophages (Figure ). To verify if virus protection is a common trait of dyes, we also tested Congo red, rhodamine B, eosin Y, SYBR green, crystal violet, and quinine to cover a wide variety of different structures and properties. All molecular structures are given in the Supporting Information. Among test dyes, Congo red provided adequate protection to phages, which aligns with our previous reports . Previously, it was found that CR specifically binds to proteins in the beta-sheets-rich fragments of the proteins and that this property is crucial for bacteriophage stabilization against UV irradiation . Eosin Y provided some protection against the UV, but a decrease in phage titer larger than 1-log was observed. Rhodamine B and crystal violet bind to the cell membrane or bacterial cell wall, respectively, but these structures are absent in bacteriophage virions. The lack of efficacy of SYBR green and quinine strongly suggests that binding to the DNA is not related to the stabilization against irradiation.