measured or observed in the mixed solution in this manner the aggregation or gelatinization in the mixed solution can be detected application_number US 201214357550 A description hereinafter embodiments of the present invention are specifically illustrated using the figures furthermore in the description below endotoxin is taken as examples and explained as the predetermined physiologically active substance but the description below can be also applied to other physiologically active substances of biological origin including u03b2 glucan in the present embodiment the substance involved in the aggregation or gelation of a coagulin for example proteins such as a coagulogen in al the al bound beads the microparticles bound with endotoxin and the like is imparted in advance with a function of generating a predetermined fluorescence when the measurement of endotoxin is performed by detecting aggregation or gelation of a coagulin produced by the reaction between endotoxin and al more specifically the predetermined fluorescent dye is bonded to the substance involved in the aggregation or gelation such as a coagulin or the al bound bead or the microparticle bound with endotoxin is formed with the inorganic fluorescent dye then when the protein aggregation or gelation is generated the intensity of the fluorescence from the fluorescent dye or the bead or the microparticle emitting fluorescence itself is measured or the fluorescence distribution is observed this makes it possible to visually observe the mechanism of the aggregation or gelation of a coagulin.