![]() ![]() Shorter wavelengths of light provide greater resolution. Resolution is the ability of the lenses to distinguish between two adjacent objects as distinct and separate.Ī compound light microscope has a maximum resolution of 0.2 µm, this means it can distinguish between two points ≥ 0.2 µm, any objects closer than 0.2um will be seen as 1 object. The nucleus and chloroplasts of eukaryotic cells can also be seen-however smaller organelles and viruses are beyond the limit of resolution of the light microscope (see Figure 1). Biologists typically use microscopes to view all types of cells, including plant cells, animal cells, protozoa, algae, fungi, and bacteria. The limit of resolution of a standard brightfield light microscope, also called the resolving power, is ~0.2 µm, or 200 nm. Since most cells are much smaller than 100 microns, we need to use microscopes to see them. Objects that are smaller than this cannot be seen clearly without magnification. The limit of resolution of the human eye is about 0.1 mm, or 100 microns (see Table 1 for metric review). This is due to the limitations of visible light (details that are smaller than the wavelength of light used cannot be resolved). (Think about magnifying a digital photograph beyond the point where you can see the image clearly). Although it is possible to magnify above 1000X, a higher magnification would result in a blurry image. Magnification refers to the process of making an object appear larger than it is whereas resolution is the ability to see objects clearly enough to tell two distinct objects apart. The total magnification will depend on which objective lens you are using-the highest magnification possible on these microscopes is typically 1000X-meaning that objects appear 1000X larger than they actually are. The microscope you will be using uses visible light and two sets of lenses to produce a magnified image. This includes human cells and many other types of cells that you will be studying in this class. What does it mean to be microscopic? Objects are said to be microscopic when they are too small to be seen with the unaided eye-they need to be magnified (enlarged) for the human eye to be able to see them. ![]()
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