SF4 Baculo Express is a special, serum-free insect cell culture medium for the cultivation of various Spodoptera frugiperda (SF9, SF21), BTI-TN-5B1-4 (High FiveTM) and Drosophila melanogaster (D.Mel-2) cells. SF4 Baculo Express is also suitable for the production of recombinant proteins and viruses. SF4 Baculo Express is a ready-to-use medium and contains all the necessary additives (steroids, amino acids, organic acids, glutamine and glucose) for the cultivation of insect cells in an optimal composition. Yeast extract has also been added to the optimized medium. SF4 Baculo Express enables high cell densities (up to 2x 107 cells/ml) and thus high yields of recombinant proteins (in bioreactors and shake flasks). In addition, the cell culture medium requires only short adaptation intervals. With some common cell lines, a direct change is even possible.