Patent ID: 8012720

Claim:
A method for detecting a protein, which comprises: (1) preparing a detecting unit having a bonding section, which has properties for specifically bonding to a protein to be detected, a sensing section made up of a polynucleotide double strand and a fluorescent pigment group, a detecting section for detecting the bonding of the protein to be detected to the bonding section, the detecting section being made up of a quenching pigment group, and a controlling section comprising a controlling unit being made up of a pair of electrodes, (2) placing the detecting unit in a container containing a sample solution comprising the protein to be detected, and (3) detecting the protein by: (a) applying an electric field to between the electrodes of the controlling section to elongate the double strand in the direction of the electric field and to set the conformation of the sensing section at an initial state, irradiating the fluorescent pigment group with light to generate fluorescence at an initial state, subsequently removing the electric field to flocculate the double strand and to observe a decrease in the intensity of fluorescence, and detect the presence of the protein by the difference in time constant during the decrease in the intensity of fluorescence between the fluorescent pigment group of the detecting unit to which the protein is bonded and the fluorescent pigment group of the detecting unit to which the protein is not bonded, or (b) irradiating the fluorescent pigment group with light to generate fluorescence at an initial state and to designate the conformation of the double strand for its initial state, applying an electric field to elongate the double strand in the direction of the electric field and to observe an increase in the intensity of fluorescence, and detect the presence of the protein by the difference in time constant during the increase in the intensity of fluorescence between the fluorescent pigment group of the detecting unit to which the protein is bonded and the fluorescent pigment group of the detecting unit to which the protein is not bonded.