Plate photos showing A: S. aureus phage plaques, B: E. coli phages plaques and C: K. pneumoniae phage plaques. (A) The plaque is circular, clear, without center, without halo, and its size is 1.5mm. (B) E. coli phage 1: plaque zone Circular, clear, without center, without halo, and its diameter is 1mm. E. coli phage 2: Circular, turbid, without center, with Halo, and its diameter is 1.5 mm. (C) Circular, clear with center, with large halo, and its diameter is 6 mm.