Fig. 1. Larval neuroblast culture. The chamber (A) is constructed from a coverslip by placing VALAP on each corner and two concentric Vaseline rings in the center. A larva is placed in the centermost ring and covered with Voltalef oil. After dissection, the brain (arrow in B) usually remains associated with the mouthparts and salivary glands, which can then be removed (C). After spreading, most cells form a monolayer (D), although some groups remain (arrows). (E) Phase-contrast image of a culture. Two neuroblasts, one in metaphase, are visible and are recognized by their large size relative to other cells. (F) Same as in E but viewed under DIC optics. See Materials and Methods for details. Bar, 20 µm (for E and F).