1. microscopy There are three well-known branches of microscopy:
optical, electron, and scanning probe microscopy.

2. Optical microscopy standard optical microscopy
(bright field microscopy)
Diffraction limits resolution to approximately 0.2 micrometres. This limits the practical magnification limit to ~1500x.

3. 雷文 霍克( )

4. 柯霍 ( )
炭疽桿菌

5. Optical microscopy
Phase contrast is a widely used technique that shows differences in refractive index as difference in contrast. It was developed by the Dutch physicist Frits Zernike in the 1930s (for which he was awarded the Nobel Prize in 1953).

6. Optical microscopy
When certain compounds are illuminated with high energy light, they emit light of a lower frequency. This effect is known as fluorescence.

8. Electron microscopy
An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. Because the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, the electron microscope has a higher resolving power than a light microscope and can reveal the structure of smaller objects.

9. Transmission electron microscope
The original form of electron microscope, the transmission electron microscope (TEM) uses a high voltage electron beam to create an image.

10. the high-resolution transmission electron microscopy (HRTEM) has allowed the production of images with resolution below 50 picometres.

11. Scanning electron microscope (SEM)
an image of an ant
the electron beam of the SEM does not at any time carry a complete image of the specimen.
When the electron beam interacts with the specimen, it loses energy by a variety of mechanisms which provide signals carrying information about the properties of the specimen surface.
The image resolution: an order of magnitude poorer than that of a TEM.
to image bulk samples
a great depth of field
images the three-dimensional shape of the sample.