Viral supernatant is usually low titer and unsuitable for most applications.  As such, viruses from media often need to be concentrated for storage or downstream applications. Benchmark Bioscience Virus Precipitation Kit provides a scalable, easy, convenient, and time-saving approach to concentrate viruses without ultra-centrifugation. The virus precipitation solution can be used for small lab samples or large-scale virus preparation with equally high yield and high viral titer. Importantly, the kit is similarly effective in the concentration of retroviruses and lentiviruses from the cell culture medium. Viruses can be concentrated 10-100 fold. The whole process uses non-toxic reagents safe for use with all target cell lines tested, including ES cells.