The InVitrus VP-6 medium is a fortified nutrient mixture for the production of recombinant proteins with several kidney cell lines, including the serum-free BHK21-InVitrus, COS-1-InVitrus and COS-7-InVitrus, and the 293-Hektor cell line. InVitrus VP-6 is typically used for batch, fed batch, and perfusion culture processes.