Cps1p assembles into the medial actomyosin ring late in anaphase. (A) Wild-type cells were stained with DAPI, TAT1 antibodies, and affinity-purified anti-Cps1p antibodies to visualize DNA, microtubules (MT), and Cps1p, respectively. (B) Cells were stained with anti-Cps1p antibodies preincubated with Cps1p-specific antigenic peptides.