Introduction to Choosing Between Inverted Microscopes and Fluorescence Microscopes
Microscope is an important instrument in cell culture and related derivative experiments. At present, there are various types of microscopes on the market, and choosing a microscope that meets the needs and is suitable is a challenge. Below, we will introduce the principles of inverted microscopes and fluorescence microscopes for easy selection.
The composition of an inverted microscope is the same as that of a regular microscope, mainly consisting of three parts: mechanical part, illumination part, and optical part. The composition of an inverted microscope is the same as a regular upright microscope, except that the objective lens and illumination system are reversed, with the former below the stage and the latter above the stage. This structure allows for a significant increase in the effective distance between the illumination focusing system and the stage, making it easier to place thicker observation instruments such as culture dishes and cell culture bottles (of course, glass slides are also acceptable), while the working distance between the objective lens and the material does not need to be very large. Inverted microscope is used by medical and health institutions, universities, and research institutes for observing microorganisms, cells, bacteria, tissue culture, suspensions, sediments, etc. It can continuously observe the process of cell and bacterial reproduction and division in culture medium, and can capture any state during this process. Widely used in fields such as cytology, parasitology, oncology, immunology, genetic engineering, industrial microbiology, botany, etc.
Fluorescence microscopy is used to study the absorption, transport, distribution, and localization of substances within cells. For the tested object, there are two ways to generate fluorescence: spontaneous fluorescence, which directly emits fluorescence after UV irradiation; Secondary fluorescence occurs when the observed object is treated with fluorescent dyes and then irradiated with ultraviolet light to emit fluorescence. Some substances in cells, such as chlorophyll, produce spontaneous fluorescence when exposed to ultraviolet radiation; Some substances themselves cannot emit fluorescence, but if stained with fluorescent dyes or fluorescent antibodies, they can also emit secondary fluorescence after being irradiated with ultraviolet light. Fluorescence microscope uses a highly efficient point light source to emit a certain wavelength of light (ultraviolet light 365nm or purple blue light 420nm) through a color filter system as excitation light, which excites the fluorescent substances inside the specimen to emit various colors of fluorescence, and then observes through the magnification of the objective lens and eyepiece. In this way, even with weak fluorescence in a strong background, it is easy to recognize and has high sensitivity. It is mainly used for the study of cell structure, function, and chemical composition.
