Required. 1) It is necessary to purify the bacteriophages from their host bacterium before proceeding to isolate DNA from bacteriophages. 2) Always have higher concentrations (upto 108 PFU/mL) of purified phage particles before starting the DNA extraction procedure.
Method: You can follow simple phenol-chloroform method for phage DNA extraction. If you can afford to buy extraction kits, it is available in Norgen, qiagen.