Color cathodoluminescence images and cathodoluminescence spectra analysis of biological materials.

Abstract

In an attempt to detect cathodoluminescence (CL), an Akashi scanning electron microscope (SEM) ISI-DS130 was remodeled into a cathodoluminescence electron microscope (CEM or fluorescence electron microscope FEM). A newly shaped mirror, combining three half ellipsoidal mirrors, was located over the specimen holder of the top stage for color CL use. The bottom stage was modified with a half ellipsoidal mirror, photomultiplier tube (PMT) and monochrometer, so that not only CL images, but also CL spectra could be obtained. An effective specimen-preparation method, known as the simple cryo-SEM method (24), was devised for CL observation.With these instruments and methods, color CL images and CL spectra of the biological substances were analyzed. Ito cells of vitamin A (vit A) -loaded rat liver and zona fasciculata cells of rat adrenal cortex emitted intense CL from their lipid droplets (LD). In order to identify the origin of this CL emission, analysis of the color CL images and the CL spectra were available.