Confocal Laser Scanning Microscopic Imaging of Subcellular Organelles, mRNA, Protein Products, and the Microvessel Environment

Abstract

The confocal laser scanning microscope (CLSM) was employed to visualize highly contrasted images of histochemically stained subcellular organelles. In early studies, only fluorescent signals were detectable by CLSM, however, recent innovations have enabled the visualization of non-fluorescent probes such as horseradish peroxidase (HRP)-diaminobenzidine (DAB). The non-fluorescent signals are permanently preserved and allow repeated or retrospective examinations. We applied CLSM to specimens prepared for light microscopy, and visualized subcellular organelles and pituitary hormone mRNA. The images were comparable to those obtained by electron microscopy (EM). We also applied this technique to the observation of tumor angiogenesis and the microvessel environment of hormone-secreting cells. Both the visualization of subcellular organelles, mRNA and protein products, and 3D images of the microvessel environment of hormone-secreting cells are discussed in this review.