FIG. 1.

Immunocytochemical characterization of microglia cells. Microglia cells were collected from mixed cultures of glia and purified by preferential adhesion. The cells were cultured on Chamber-Tech slides as adherent monolayers for 7 days. They were then fixed with cold acetone-methanol (1:1) for 15 min and treated with anti-CD68 (A) or anti-HAM-56 (B) to confirm their identity. The cells were immunoreactive for CD14 (C). Incubation with vimentin (D) demonstrated processes extending from the cell bodies. Double immunostaining for HLA-DR and HAM-56 revealed the presence of major histocompatibility complex class II on some cells. The preparations were devoid of any astrocytes as demonstrated by double labeling with HAM-56 (G) and GFAP (H), an astrocyte marker. Positive staining was visualized by anti-mouse IgG labeled with FITC for CD68, vimentin, CD14, and HLA-DR. Anti-mouse IgM labeled with TRITC was used for HAM-56. GFAP staining was visualized with anti-rabbit rhodamine. All observations were made on a Nikon Microphot FXA microscope with appropriate filters. Original magnifications, ×200 (A, B, C, D, E, and F) and ×400 (G and H).