Often experimentalists require a quantitative assessment of the levels of heterologously expressed proteins to best interpret changed Ca(2+) signaling patterns. Here, we detail a rapid and convenient western blotting method for individual Xenopus oocytes. The method exploits recently introduced rapid blotting systems, commercially available from Invitrogen (iBlot) or Bio-Rad (Trans-Blot Turbo). The key advantage is speed: from live cell to transferred membrane in <1 h. Therefore, oocytes can be conveniently processed for western blotting to assess relative expression levels, even after a long day of Ca(2+) imaging experiments.