FIG. 6.

Infection by heat-treated phage particles. Fusion kinetics were studied in 50 mM sodium phosphate buffer (pH 7.0) at room temperature. In the case of unheated phage φ13 (A) and φ6 (C) particles, the infection MOI was 10, and the same amounts of viruses were used after heating. The capability of the phage φ13 (B) and φ6 (D) particles to form infective centers was assayed after virus incubation at different temperatures for 10 and 15 min, respectively. (E) The TPP⁺ uptake experiments were performed at 28°C in 50 mM sodium phosphate buffer (pH 7.0). The cells were added to obtain the final concentration of 2 × 10⁸ CFU/ml. The MOI was 10 in the case of unheated phage infection, and the same amounts of particles were used after the heating. Curves: 1, HB10Y cells infected with unheated φ13; 2 and 3, LM2509 cells infected with φ13 heated for 10 min at 33 and 30°C, respectively; 4, LM2509 cells infected with unheated φ13. The arrow indicates the addition of phage.