Fig. 3. Control experiments on sections of a ventral photophore from the hatchetfish, Argyropelecus hemigymnus. Preabsorption using antigen (block peptide, Table 1) and the antibody nNOS sc1025 (A and B) resulted in quenching of the immunoreaction both in the filter cells (compare A and C) and among the photocytes (compare B and D). f, filter cell area; p, photocytes; r, reflector. Bars, 50 µm.