Patent ID: 8384044

Claim:
A fluorescence reading apparatus 12 that detects a specific interaction between a probe substance and a target substance, comprising: a substrate 2 to which a probe substance 1 is fixed; a sample chamber 6 that accommodates the probe substance 1 and also accommodates a sample 5 that contains a fluorescent substance 3 and a target substance 4 such that the sample is brought into contact with the probe substance 1 ; a light source 7 ; an optical system 8 that guides the light from the light source 7 to the substrate 2 to generate an evanescent field; and a fluorescence detecting unit 9 that detects a fluorescence intensity or a fluorescence image generated by the fluorescent substance 3 excited by the evanescent field, wherein the optical system 8 comprises an incidence angle adjusting means 10 for adjusting an incidence angle when the light from the light source 7 is incident on the substrate 2 ; and a controller 11 that controls an amount of the incidence angle adjusted by the incidence angle adjusting means 10 ; wherein the controller 11 comprises a means for receiving information on the incidence angle adjusted by the incidence angle adjusting means 10 and information on the fluorescence intensities or fluorescence images at a plurality of incidence angles detected by the fluorescence detecting unit 9 and obtaining the penetration depths of the evanescent fields with respect to the plurality of incidence angles from the information on the incidence angles; and a means for obtaining information on the fluorescence intensities in the obtained plurality of penetration depths; and wherein the controller comprises a means for obtaining a graph, using the relationships between the penetration depths of the evanescent fields and the fluorescence intensities with respect to the plurality of penetration depths, where one axis represents the fluorescence intensity while the other axis represents the penetration depth of the evanescent field.