ORGANIC COLORED MICROPARTICLES, DIAGNOSTIC REAGENT KIT, AND IN VITRO DIAGNOSIS METHOD

The present invention provides organic colored microparticles used in an immunochromatography diagnostic kit, the microparticles having good background and test result reproducibility and sufficient detection sensitivity. These organic colored microparticles are characterized in that the average particle diameter is 100 to 650 nm; coloration intensity is 1.0 to 10.0; when a total of 100,000 particles are detected within a particle diameter range of 400 to 12,000 nm, the percentage of coarse particles having a particle diameter of 700 nm or greater is 5% or less; and the sphericity representedby the major axis (L)/minor axis (D) is 1.0 to 2.5. 提供具有良好的本底和检查结果的再现性、具有充分的检出灵敏度的免疫色谱诊断试剂盒中使用的有机着色细颗粒。本发明的有机着色细颗粒的特征在于，平均粒径为100～650nm，显色强度为1.0～10.0，长径(L)/短径(D)所示的球形度为1.0～2.5，并且，在粒径400nm～12000nm的范围内检测总个数100000个颗粒时，粒径700nm以上的粗大颗粒的存在率为5％以下。