Phage lysis of host bacteria can be visualized by plaque formation on lawns of host cells in soft agar overlayed on agar plates (Adams, 1959; Sambrook et al. 1989). This principle can be used for the detection and subsequent isolation of specific lytic phages in environmental samples (e.g., Carlson 2005). Spotting environmental samples on lawns of a target host cell would thus reveal the presence of a lytic phage for that particular host cell in the given sample.