Abstract: A lighting apparatus for causing the light from a light source to enter the incident surface of a light guide plate and to project the light toward an object of illumination from the exit surface of the light guide plate extending in the direction perpendicular to the incident surface. The light source is made by placing a light-emitting diode on or near the light source rod extending in the longitudinal direction parallel to the incident surface of the light guide plate. The light source rod and the light guide plate are integrally made by forming a slot in a common plate.

Abstract: A flowcell for containing sample solutions is surrounded by an electric heater which is then surrounded by an isothermal frame having a large heat capacity, and a Peltier element serving as a cooling source is coupled with the isothermal frame. A heat delaying plate is arranged between the flowcell and heater and a temperature sensor is arranged between the flowcell and the heat delaying plate. The Peltier element is controlled in such a manner that the temperature of the isothermal frame is maintained substantially at a constant temperature lower than a predetermined temperature at which the sample solution is to be kept. The heater is controlled in accordance with a difference between the temperature of the sample solution and the predetermined temperature.