Fig. 1From: A novel detection methodology for HER2 protein quantitation in formalin-fixed, paraffin embedded clinical samples using fluorescent nanoparticles: an analytical and clinical validation studyStructure of PID nanoparticles and binding method with antigen. PID nanoparticles consist of approximately 100,000 perylene diimide, and its surface was coated with streptavidin via PEG chains. The staining method using PID is in principle similar to classic immunohistochemistry (IHC). PID nanoparticles bind to antigen on the specific protein via primary antibody and biotin labeled secondary antibody. These nano-particles are 10,000 times brighter compared to conventional organic dyes, with high photostabilityBack to article page