Fig 3.

Moving-bin histogram of granule equivalent volumes calculated by using transmission electron micrographs to measure cross-sectional areas of cytoplasmic granules in rat peritoneal mast cells. In (A), data for 2327 granules are presented using bin sizes of 0.0036 μm³ (upper curve) and 0.0072 μm³ (lower curve). In (B), a bin size of 0.0045 μm³ is used to compare data obtained from 2327 granules (upper curve) versus the first 1050 granules measured (lower curve). The arrows (V₁, V₂, V₃, etc.) are placed at integral multiples of the mean intermodal distance calculated for each curve, a value that defines the magnitude of the ‘unit volume’. (Modified from [27], with the permission of the publisher.)