A convenient culture chamber for observation and embedding of macrophage monolayers for transmission electron microscopy.

A chamber adapted from a polypropylene test tube is described for the cultivation and processing of undisturbed monolayers of normal mouse macrophages for transmission electron microscopy (TEM). Peritoneal exudate cells are grown in the chambers on Visking dialysis membranes pretreated with Polybrene (Sigma Chemical Co.) and normal mouse serum. The cells are not further disturbed after adherence since the entire chamber, including dialysis membrane and cells, is processed for electron microscopy using standard material and protocols and the embedded dialysis membrane is readily oriented and thin-sectioned. This method is efficient for studying adherent cells since growth can be nearly confluent and cells remain firmly attached throughout the manipulations. Since a transparent membrane is used, cells can also be observed with the light microscope at all stages prior to sectioning.