Culture and recovery of macrophages and cell lines from tissue culture-treated and -untreated plastic dishes.

Macrophages can be separated from other cell types by their ability to readily attach and spread on glass or on plastic surfaces which are treated for optimal growth of cultured cells (tissue culture-treated plastic). To detach macrophages from these surfaces, techniques must be used which require prior preparation of special flasks or vessels, utilize expensive equipment, are time-consuming and almost uniformly require that the macrophages be exposed to various chemicals. We now report that macrophages can be enriched and recovered efficiently after attachment to disposable polystyrene bacteriologic petri dishes simply by gentle scraping with a rubber policeman. In this paper we compare this method to others currently in use in which resident peritoneal cells, peritoneal exudate cells or cells from bone marrow-derived cultures are detached from treated dishes using cold shock, chelating agents and lidocaine. In all studies, advantages were noted when cells were incubated in untreated dishes and detached by gentle scraping. In addition, untreated dishes supported the growth of adherent cell lines IC-21 and L929B and yielded large numbers of cells, with high viability, which were easily harvested.