Difference Between Ordinary Light Microscope and Fluorescence Microscope
Optical microscope: It is an optical instrument that uses optical principles to magnify and image tiny objects that cannot be resolved by the human eye, so that people can extract microstructure information.
Fluorescence microscope: Fluorescence microscope uses ultraviolet light as the light source to irradiate the object under inspection to make it emit fluorescence, and then observe the shape and location of the object under the microscope. Fluorescence microscopy is used to study the absorption and transportation of substances in cells, the distribution and localization of chemical substances, etc. Some substances in cells, such as chlorophyll, can fluoresce after being irradiated by ultraviolet rays; although some substances themselves cannot fluoresce, they can also fluoresce after being stained with fluorescent dyes or fluorescent antibodies after being irradiated by ultraviolet rays. Fluorescence microscopy is one of the tools for qualitative and quantitative research on such substances.
An optical microscope generally consists of a stage, a spotlight lighting system, an objective lens, an eyepiece, and a focusing mechanism. By changing the lighting method, the spotlight lighting system can obtain different observation methods such as dark object points on a bright background (called bright field illumination) or bright object points on a dark background (called dark field illumination), so as to better discover and observe microstructures in different situations.
Fluorescence microscopes differ from ordinary microscopes in the following ways:
1. The illumination method is usually episcopic, that is, the light source is projected on the sample through the objective lens;
2. The light source is ultraviolet light, the wavelength is shorter, and the resolution is higher than that of ordinary microscopes;
3. There are two special filters, the one in front of the light source is used to filter out visible light, and the one between the eyepiece and objective lens is used to filter out ultraviolet rays to protect human eyes.
Fluorescence microscope is also a kind of optical microscope, the main difference is that the excitation wavelength of the two is different. This determines the difference between the fluorescence microscope and the ordinary optical microscope in terms of structure and usage.
Fluorescence microscopy is an essential tool in immunofluorescent cytochemistry. It is composed of main components such as light source, filter plate system and optical system. It is to use a certain wavelength of light to excite the specimen to emit fluorescence, and to observe the fluorescence image of the specimen by amplifying the objective lens and eyepiece system.
