Phage Stability in Storage Solutions

Phage stocks were diluted to 10 mL, in triplicate in five different solutions to produce different starting concentrations, i.e., 9 and 7 log pfu/mL in 15 mL polypropylene tubes (GreinerBioOne, Vilvoorde, Belgium), and stored at 4 °C.
Five different solutions used were: 5% glucose infusion solution (Fresenius Kabi, Schelle, Belgium); 0.9% NaCl infusion solution (Fresenius Kabi, Schelle, Belgium); Hartmann infusion solution (Baxter, Lessines, Belgium); DPBS supplemented with (w/) Ca²⁺ and Mg²⁺ (Lonza Biosciences, Verviers, Belgium); and without (w/o) Ca²⁺ and Mg²⁺ (Lonza Biosciences, Verviers, Belgium). Table 2 summarizes the detailed composition and characteristics of the five storage solutions. Phage infectivity was tested by determination of phage titer with the double agar overlay method on propagating bacterial strains, as described previously [25 (link)].