I am currently trying to use a commercial "PEG Virus Precipitation Kit" to concentrate my baculovirus. After I add the PEG to my viral supernatant I will get a very large pellet. However this pellet is almost completely insoluble in the resuspensionbuffer. If I centrifuge again I can get rid of the unsoluble pellet by transfering the supernatant to another tube but after adding this to my cells I can not see any signs of infection compared to unconcentrated controls. Has anyone used PEG concentration for baculovirus before and has any ideas? Thank you in advance!