Action of the bacterial neutral protease, dispase, on cultured cells and its application to fluid suspension culture with a review on biomedical application of this protease.

The bacterial neutral protease from Bacillus polymyxa, dispase, has been characterized using 21 mammalian cell lines in its cell-dispersing capability, cytotoxicity, and effects on cell growth. The previous observation that fibroblast-like cells are detached by this protease from culture substrate, as well as dissociated into a monodisperse cell suspension, while that epithelial-like cells are detached but not completely dissociated, was generally confirmed, although exceptions to these general rules were noted. Efforts were made here by the use of dispase to develop techniques for suspension culture and single cell plating: Successful conditions of suspension culture for 6 lines, and single cell plating for 3 lines were respectively described. Key factors in these techniques were choice of a low concentration of dispase in growth media to avoid its cytotoxic effect, and choice of appropriate serum concentration in the medium to allow this protease to remain active. Recent literatures on the application of dispase in biomedical science were reviewed.