Maximum number of magnifications for a microscope

In summary: Additionally, there are techniques such as superresolution microscopy that can surpass the diffraction limit and achieve resolutions on the order of nanometers using visible light sources. Two examples of these techniques are PALM and STED, which were awarded the Nobel Prize in Chemistry in 2014.
  • #1
meteor
940
0
Don't know where to post this, I hope is in the right place. What's the maximum number of magnifications that a microscope (of any class) has achieved to date? I want concrete ciphers.
 
Last edited by a moderator:
Biology news on Phys.org
  • #2
"Number" as in different magnification steps? You can magnify an image as much as you want, that is not the relevant quantity. The resolution is the interesting property, it is generally limited by the wavelength of the light or particle used to make the image: Visible light won't resolve structures smaller than ~200 nm, UV can resolve smaller structures but is likely to destroy chemical bonds. Electron microscopes can image individual atoms.
 
  • #3
As @mfb mentioned, the important quantity in microscopy is resolution. Standard microscopy is diffraction-limited, meaning that the smallest resolved feature is on the order of the wavelength. In the case of visible light, this is about 200 nm. In the case of electrons, this can be angstroms.

However, the diffraction limit is a far-field effect (where the distance between the sample to image and the objective is large compared to the wavelength), and there are several techniques in existence nowadays for going beyond it ("superresolution microscopy"). These generally fall into 2 camps (below). The resolution for each is on the order of single nanometers when using visible light as the source.

The first is to use a near-field probe, where the distance between sample and objective is on the order of the wavelength or less. This is an active field of research and has only recently become feasible, mainly because Maxwell's equations in the near-field are much more complicated than in the far field (the desired information is contained in non-propagating evanescent surface waves), and their solution requires a fair degree of computational power.

The second technique is to use far field imaging along with some clever way of localizing light sources. The two most famous examples of this technique--awarded the Nobel Prize in Chemistry in 2014--are PALM (photoactivated localization microscopy) and STED (stimulated emission depletion). The techniques differ in their details, but both are based on the idea that a fluorescing molecule will display its light according to a predictable point spread function. If the point spread functions of two closely (sub-diffraction limit) spaced fluorophores can be distinguished, their most likely positions can be computed and an image can be built up. PALM does this by using different fluorophores of different colors, while STED does this by using partially overlapping lasers: one to excite a group of fluorophores and one to de-excite part of that group.
 
  • #4
meteor said:
Don't know where to post this, I hope is in the right place. What's the maximum number of magnifications that a microscope (of any class) has achieved to date? I want concrete ciphers.

As a rule of thumb, the maximum 'useful magnification' in light microscopes under standard widefield conditions is approximately 1000 x (numerical aperture). For electron microscopes, the accelerating voltage is used instead of numerical aperture, and from what little I understand, the maximum useful magnification is about 1000 x (accelerating voltage)
 
  • Like
Likes Greg Bernhardt

What is the maximum number of magnifications for a microscope?

The maximum number of magnifications for a microscope depends on the type of microscope being used. Generally, compound microscopes have a maximum magnification range of 1000x, while electron microscopes can have a maximum magnification of up to 1 million times.

What factors affect the maximum number of magnifications for a microscope?

The maximum number of magnifications for a microscope is affected by several factors, including the type of microscope being used, the quality of the lenses, and the resolution of the microscope. Additionally, the quality of the specimen being viewed can also impact the maximum magnification.

Why is the maximum number of magnifications important for a microscope?

The maximum number of magnifications is important for a microscope as it determines the level of detail that can be seen in a specimen. The higher the magnification, the finer the details that can be observed, which is crucial for scientific research and analysis.

Can the maximum number of magnifications be increased?

The maximum number of magnifications for a microscope is limited by the technology and design of the microscope. While it may be possible to increase the magnification range through modifications or upgrades, there is a physical limit to how much a microscope can magnify an image.

What happens if the maximum number of magnifications is exceeded?

If the maximum number of magnifications for a microscope is exceeded, the image will become blurry and distorted. This is because the microscope is unable to resolve the fine details at such high magnifications, resulting in an unclear image. It is important to use the appropriate magnification for the specimen being viewed to ensure accurate observations.

Similar threads

Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
12
Views
2K
  • DIY Projects
Replies
4
Views
307
Replies
5
Views
1K
Replies
5
Views
7K
  • Materials and Chemical Engineering
Replies
21
Views
1K
Replies
7
Views
2K
  • Atomic and Condensed Matter
Replies
6
Views
2K
Replies
2
Views
872
  • Other Physics Topics
Replies
32
Views
8K
Back
Top