The electrical characterization of a biohybrid integrated circuit is described. Uromyces appendiculatus is the biological moiety and an integrated circuit provides the electrical interface between the biological element and the test equipment. Direct current characterization has shown the current flow to be nonlinear with a time constant of 30-60 s. The conductivity is believed to be ionic through intracellular ions of the fungal cell. Locations of the germ tube which have different ion compositions have shown contrasting responses to testing over time. Potential applications are reviewed.