Abstract: A method for assaying a substance is provided in which an optical image is obtained from spots of light emitted from a chemiluminescent material capable of undergoing a luminescent reaction. The method comprises: (a) a step of distributing solid particles on the surface of a support, the solid particles having a diameter of not more than 100 .mu.

Abstract: The present invention provides a chemiluminescence measuring apparatus which is small in size and high in operability and has a function of performing accurate quantitative analysis and the like. The apparatus includes at least a box-like housing having an opening, a cover provided on a top surface of the housing and having a through hole for introducing a first detachable vessel into the inner space of the housing, a holder having a concave portion and enclosing the opening of the housing, the hollow chamber having an opening at a side wall thereof and partially housing a second vessel, a photo-sensing unit for detecting luminescence from the second vessel via the through hole of the hollow chamber, and a shutter mechanism for intermittently cutting optical path between the photo-sensing unit and the second vessel.

Abstract: The first branch 1a of the optical fiber 1 is connected to the light source 2, and the second branch 1b is connected to the optical measuring unit 3. A taper-shaped tip member 8 is fitted to a tip end of the optical fiber unit 1 with the use of a jig member 4. The inner hollow space 7 in the tip member 8 is connected with the air suction device 11, through the gap 5 formed between the optical fiber unit 1 and the jig member 4 and the air suction tube 10. The air suction device 11 discharges air from the inner hollow space 7 to suck liquid through the through-hole 6 into the inner hollow space. The air suction device 11 is controlled by the controller 12. Because the optical fiber unit can directly irradiate liquid with light, measurement can be performed with high sensitivity. The optical fiber unit is prevented from contamination.