Phage on a petri-dish can be isolated for further study.
If you are considering this method, congratulations are probably in accord! You have most likely isolated a unique phage. To study your phage further, this method allows for the selection of a plaque that began from a unique virus, and allows for the expansion of the plaque for further purification and study.
1) Using a pipette tip, plastic bacterial loop, sterilized toothpicks, or anything else that is sterile such as a bacterial inoculation loop, carefully scoop up only the plaque area from a single plaque. You will be capturing M. smegmatis and a portion of the agar beneath the plaque, this is expected.
2) Transfer the phage plaque into 1 mL sterile MP buffer, within a micro-centrifuge tube. Mix the plaque with the MP buffer by pipetting up-and-down a bit. Incubate at room temperature for 2 hours, preferably on a platform shaker.
3) Phage Dilution Plating. Dilute the plaque to 100, 10-1 and 10-2 for plating. The objective is to make lacy plates that can be extracted from the plate.