Fig. 3. Mad2 and 3F3/2 phosphoprotein double immunolabeling of an early grasshopper spermatocyte. (A) Mad2 immunofluorescence (green) superimposed on a phase contrast image. (B) 3F3/2 immunofluorescence (red) superimposed on the phase contrast image. In this early cell, one chromosome (asterisk) is improperly attached – both kinetochores (yellow arrows) are attached to the same (upper) pole and other chromosomes have only recently attached as shown by high 3F3/2 brightness of some kinetochores (blue arrow). The upper spindle pole (p) is labeled with 3F3/2 and the approximate position of the lower pole is indicated (p). Bar, 10 µm.