Abstract: In the method for measuring cell counts or methane producing activity of Methanogens according the present invention, an extracted liquid is prepared by adding an addition solution for extracting a particular fluorescent substance inherent to Methanogens, for example, F.sub.420 exciting in the energy metabolism system of Methanogens in the object for examination and functioning as the electron carrier in the electron transport system or by heating the first object for examination. Since a particular fluorescent substance existing in the Methanogen cells in the first object for examination has been extracted out of the Methanogen cells, the intensity of fluorescence is increased upon measurement thereof.

Abstract: A logic circuit has the first electron transmission protein film made of the first electron transmission protein, the second electron transmission protein made of the second electron transmission protein having a redox potential different from that of the first electron transmission protein and glued on top of the first electron transmission film, the third electron transmission protein made of the third electron transmission protein having a redox potential different from that of the second electron transmission protein and glued on top of the second electron transmission protein film, an electrode connected to the first electron transmission protein film, an electrode having an electrical influence on the second electron transmission protein film, and an electrode connected to the third electron transmission protein film to form transistors making use of differences in redox potential among the respective electron transmission proteins for performing a logical operation for a plurality of inputs.

Abstract: The present invention relates to a redox electric element circuit formed by using oxidation-reduction substance such as electron-transport protein or the like. Oxidation-reduction substance arranged between redox electric elements and the like is inactivated by energy beam irradiation to form insulating matter, so that wirings and element separation structure are established between redox electric elements and the like.

Abstract: Layers constituting a rectifier or transistor element are respectively formed by oxidation-reduction substances so that a redox potential difference is provided between adjacent layers. The oxidation-reduction substances are selected from biogenic redox protein, pseudo-redox protein and the like. The element is implemented in hyperfine size in molecular level, so that an integrated circuit of super-high density can be attained by using the element.

Abstract: An electronic device comprises a substrate (16) of glass, a plurality of elongated electrodes (17) which are provided in parallel with each other on the glass substrate, a first electron transport protein film (18) prepared by cytochrome c formed on the electrodes, a second electron transport protein film (19) of flavodoxin adhered and joined on the first electron transport protein film and a plurality of elongated electrodes (20) provided in parallel with each other on the second electron transport protein film. Cytochrome c is different in redox potential from flavodoxin, whereby rectifying characteristics are attained in the device in a molecular level by junction of the first electron transport protein film (18) and the second electron transport protein film (19).