Types of 3D Microscopes
There are three types of microscope with the ability to produce three-dimensional images. The scanning electron microscope (SEM) and transmission electron microscope (TEM) both use beams of electrons to produce an image of the sample. The confocal laser scanning microscope uses a laser beam to produce an image. Although these microscopes can produce 3D images, they are also used to produce 2D images.
Scanning Electron Microscope
Scanning electron microscopes are very powerful; they have the ability to magnify a sample up to 500,000 times. The electron beam is very thin, allowing for high-resolution images. The most powerful scanning electron microscopes can distinguish between objects 1-5nm apart. Due to the nature of the electron beam, the scanning electron microscope produces images with shaded edges, giving them a three-dimensional look.
Transmission Electron Microscope
Transmission electron microscopes are also very powerful, they have the ability to magnify a sample up to 750,000 times. Some transmission electron microscopes have a resolution able to separate objects only 1nm apart. By producing multiple images of the same sample at different angles you can create 3D images using an transmission electron microscope.
Confocal Laser Scanning Microscope
Confocal laser scanning microscopes are able to distinguish between different depths of a sample. Using a computer, many images are produced at selected depths. Once recombined, the different images can be put together to produce one 3D image of the original sample. A confocal laser scanning microscope allows more detailed images of samples to be produced by using multiple different focuses on one image. This allows confocal laser scanning microscopes to surpass the ability of light to distinguish between different levels of a complex sample.
References & Resources
- AH Jansson: Three-dimensional transmission electron microscopy
- National Institute of Health: 3D Imaging of Diatoms with Ion-abrasion Scanning Electron Microscopy
- Oxford Journals: 3D Confocal Laser Scanning Microscopy for the Analysis of Chlorophyll Fluorescence Parameters of Chloroplasts in Intact Leaf Tissues