Why is an inverted microscope called an "inverted" microscope?
The composition of an inverted microscope is the same as that of a regular microscope, except that the objective lens and lighting system are reversed, and the object is located in front of the objective lens, with a distance from the objective lens greater than the focal length of the objective lens, but less than twice the focal length of the objective lens. After passing through the objective lens, an inverted magnified real image is formed. What our eyes see through the eyepiece is not the object itself, but the magnified image of the object formed by the objective lens.
Due to the fact that the materials observed by inverted microscopes are generally cultured cells with high transparency and unclear structural contrast, inverted microscopes are often equipped with phase contrast lenses, which in fact constitute inverted phase contrast microscopes.
On inverted microscopes, various types of consumables such as culture dishes and porous plates are often used, with varying thicknesses at the bottom, which can cause certain changes in the passage of light. At this point, it is necessary to use an objective lens with a correction ring function, which is equipped with a ring mounted adjustment ring in the middle. When the adjustment ring is rotated, the distance between the lens groups inside the objective lens can be adjusted to correct the aberration caused by the non-standard thickness of the cover glass (culture dish) (conventional culture dish is 1.2mm, cover glass is 0.17mm). The correct usage method is to adjust the calibration ring to the standard value of 1.2mm and focus on the sample. Adjust the correction ring to the right half grid, and then focus on the sample. If the image effect improves, adjust it to the right and then focus again, and vice versa.
Inverted biological microscope achieves dual channel function. The product has added an infinite high beam path that allows you to introduce additional light sources and achieve technologies such as FRAP, photoactivation, laser ablation, laser tweezers, or photogenetics.
Inverted microscopes were born to adapt to microscopic observations in fields such as biology and medicine, such as tissue culture, cell culture in vitro, plankton, environmental protection, and food inspection. Due to the special limitations of these samples, the tested objects are all placed in culture dishes (or culture bottles), which requires a long working distance between the objective and condenser lenses of the inverted microscope, allowing for direct microscopic observation and research of the tested objects in the culture dishes. Therefore, the positions of the objective lens, condenser, and light source are all reversed, hence the name "inverted".
