Patent ID: 7102754
Filing Date: 2006-09-05
Classification: G01N

Abstract:
1. A measuring method for detecting a state of attenuation in total internal reflection by the use of a measuring apparatus comprising a measuring unit comprising a first light source emitting a first light beam; a measuring chip comprising a first dielectric block transparent to the first light beam, a first film layer formed on one face of the first dielectric block and a first sample liquid holding system which holds a first liquid on the surface of the first film layer; a sensing material which can be combined with a specific material in the first liquid and is disposed on the first film layer; a first optical system which causes the first light beam to enter the first dielectric block to impinge upon the interface of the first dielectric block and the first film layer at various angles of incidence so that total internal reflection conditions are satisfied at the interface; and a first photodetector means which detects the intensity of the first light beam reflected in total internal reflection at the interface of the first dielectric block and the first film layer, a reference unit comprising a second light source emitting a second light beam; a reference chip comprising a second dielectric block transparent to the second light beam, a second film layer formed on one face of the second dielectric block and a second sample liquid holding system which holds a second liquid on the surface of the second film layer, a second optical system which causes the second light beam to enter the second dielectric block to impinge upon the interface of the second dielectric block and the first film layer at various angles of incidence so that total internal reflection conditions are satisfied at the interface; and a second photodetector means which detects the intensity of the second light beam reflected in total internal reflection at the interface of the second dielectric block and the second film layer, and a measuring means which corrects result of detection by the first photodetector means on the basis of result of detection by the second photodetector means and measures the change of a state of attenuation in total internal reflection on the basis of the corrected result of detection by the first photodetector means, wherein the measuring method comprises detecting the difference in sensitivity between the measuring unit and the reference unit before initiating the measurement of the change of a state of attenuation in total internal reflection, and calibrating result of measurement by the measuring means on the basis of the difference in sensitivity between the measuring unit and the reference unit.