Hi Nicola,

You can remove PEG from the solution by an addition of an equal volume of chloroform (assuming that your phage is not sensitive to chloroform) followed by centrifugation at 3,000 x g for 15 minutes at 4oC. Once this step has been completed, pellet the bacteriophages by centrifugation at 25,000 xg for 60 minutes at 4oC, discard the supernatant and resuspend the pellet in 0.1 M ammonium acetate (pH7). This process should be repeated at least twice.The phages can then be examined by TEM. Note that examination of CsCl purified phages always yields cleaner samples. PEG precipitated phage samples will always contain host cell debris such as cell wall fragments. For detailed discussions and methods relating to the examination of phages by transmission electron microscopy refer to articles published by Professor Hans-Wolfgang Ackermann.