Fig. 3. Colocalisation of VOCCs and RyRs in ventricular, atrial and neonatal rat cardiac myocytes. Panels A, B and C depict immunostained adult ventricular, adult atrial and neonatal ventricular myocytes, respectively. The left-hand panels (Ai, Bi and Ci) show cells immunostained with a polyclonal antibody raised against the 1_c subunit of L-type VOCCs (CNC1; a kind gift from Prof. W. Catterall, Dept. of Pharmacology, University of Washington, Seattle). The middle panels (Aii, Bii and Cii) display cells immunostained with a monoclonal antibody raised against type 2 RyRs (Calbiochem; C3-33). The right-hand panels (Aiii, Biii and Ciii) depict a merge of the VOCC and RyR images. The neonatal myocyte nuclei were visualised using DAPI staining (blue). Specific immunostaining was visualised using secondary antibodies conjugated to Alexa Fluor 488 or 568. Bars, 10 µm.