Density-Dependent Colour Scanning Electron Microscopy (DDC-SEM). Applications in the study of calcified tissues and visual impact.

Abstract

Scanning Electron Microscopy (SEM) is widely used as a technique for materials characterization. It has also been successfully applied to the imaging of biological samples, providing invaluable insights into the topography, morphology and composition of biological structures. A particular method combining different SEM detectors, named Density-Dependent Coloured SEM (DDC-SEM), has proven to be most useful for the identification and visualization of minerals in soft tissues. The method consists of a manipulation of original greyscale SEM images to produce coloured images that provide both topography and density information for samples with components of different densities. Here we provide a discussion on how to use DDC-SEM to aid the visualization and intuitive understanding of pathological calcification. This method has become popular not only for its scientific improvement of conventional SEM greyscale images, but also for its aesthetical merits. Lay summaryScanning Electron Microscopes (SEM) are widely used tools for examining biological materials such as human tissue. Like other electron microscopes, it only produces images in greyscale. SEM has been useful, for instance, in improving our understanding of calcific diseases. These diseases involve the build-up of mineral in the bodys soft tissues, and frequently affect the heart, kidneys, or eyes. This work provides a discussion on using a SEM technique known as Density-Dependent Colour Scanning Electron Microscopy (DDC-SEM), which enhances SEM images through scanning the same area with different detectors, assigning a unique colour to each detectors output, and then overlaying these images.