A high throughput biological screening assay comprising at least two anodes, at least two cathodes acting as the reference electrode, and a polymer membrane placed between each anode and cathode, wherein the at least two anodes comprise a biological culture, and wherein the at least two cathodes comprise an oxidizing agent and a buffering agent. The high throughput biological screening assay wherein the at least two cathodes are connected in parallel to simulate the connection between the same cathode and different anodes. The high throughput biological screening assay further including an external resistor or open circuit and means for measuring the voltage across the external resistor or open circuit. A method of measuring power generation using a single cathode as a reference electrode to monitor the biological production of energy. A method of correlating bacterial biofilm formation within an operational microbial fuel cell directly to current output.