What is phase contrast microscopy or phase contrast microscopy.
The reason why images of unstained tissues, cells, viruses, and other living organisms are invisible to ordinary light microscopes is that the difference in the change of light passing through the sample (contrast) is small. Staining of the specimen changes the amplitude (brightness) and wavelength (colour), affecting the contrast and obtaining an image. However, staining causes distortion of the sample and can also cause living organisms . To observe fresh tissue, cells or other tiny living organisms without staining a phase microscope must be used. The principle of the phase microscope is that two light waves interfere with each other due to a phase difference, resulting in a change in the intensity and contrast of the light waves and a visible image. The light emitted from a point light source can be represented as a sine wave pattern. The distance between the two peaks of the wave is the wavelength, and the amplitude of the wave indicates the brightness of the light (large amplitude, high brightness). Imagine the same light source emits two light waves, respectively, through the air and a transparent medium. Through a certain thickness of a transparent medium, the speed of the light wave will be reduced, but the brightness of the light remains unchanged. Light waves in the transparent medium through the wavelength than has been in the air forward of another light wave lag, so the two light waves appeared to change the phase (phase difference). However, the human eye cannot distinguish the phase difference between these two parallel rays of light. If the two light waves to the same point of the light screen, and a light wave than another light wave lagged half a wavelength, that is, the two light waves due to the phase of the opposite and interfere with each other to cancel out the disappearance of the light, or the relative amplitudes of each other and the light is weakened. If a light wave although a wavelength of hysteresis, but two light waves in the same phase, the superposition of waves and light enhancement.
In short, the phase microscope is the use of samples in the mass of the refractive index of the different or the thickness of the mass of the inequality of the phase difference of the light, so that fresh specimens do not have to be stained can be seen, and can be observed in living cells such as mitochondria and chromosomes and other fine structures, but also can be applied to moulds, viruses, and other more tiny living organisms of the study of specimens morphology, quantity, activity and division, reproduction, and other biological behaviours, observation, and can be Measurement and comparison. Phase microscope is the use of samples in the mass of the refractive index of the different or the thickness of the mass of the inequality of the phase difference of the light, so that fresh specimens do not have to be stained can be seen, and can be observed in living cells, such as mitochondria and chromosomes and other fine structure, but also can be applied to moulds, the military, viruses, and other smaller living organisms for the study of specimens morphology, quantity, activity and division, reproduction, and other biological behaviours, observation and can be measured and compared. Measurement and comparison.
