I have a mixture of adenovirus and AAV. I would like to remove the AAVs and leave only the adenovirus. Due to unique circumstances (that are unfortunately proprietary), I am unable to use affinity methods. As such, I am looking for a size-based method of removing the ~25 nm AAVs from the ~100 nm adenovirus. I've had trouble with CsCl gradient ultracentrifugation, so I'm trying to develop a custom vacuum filtration setup, but that is looking challenging as well. Any suggestions?