phase change refers to the changes in the amplitude, and wavelength of the light when it passes from one medium to the other...
phase contrast
The phase contrast microscope was invented in 1934 by Dutch physicist Frits Zernike. His innovation allowed for the visualization of transparent biological specimens that were previously difficult to see using traditional microscopes.
The microscope that is used to see internal structures of cells in a natural state is the compound light microscope. The microscope has a lens and light that allows it to see the internal structures of a cell clearly.
Phase-contrast microscope utilizes phase shifts in light passing through a transparent specimen to enhance contrast, making transparent objects more visible without staining. Brightfield microscopes rely on absorption of light by the specimen to create contrast, typically requiring staining to visualize transparent specimens effectively.
Using a phase-contrast microscope
Stereomicroscope, Compound Microscope, Phase-contrast microscope, electron microscope, Scanning-electron microscope, Transmission electron microscope, Confocal-scanning microscope. THESE ARE JUST SOME. :)
A phase-contrast microscope (or phase-difference microscope or phase microscope) allows better viewing of clear specimens that usually need to be stained before you can make out the various parts. Staining is a time consuming process and kills the cells being viewed. With a phase-contrast microscope, living cells can be studied as they go through the cell division cycle.HOW IT WORKSAs light goes through a transparent specimen, there may not be anything interesting to see. However, the light undergoes phase changes as it passes through the different parts of the specimen. Unfortunately, the human eye does not notice phase changes. A phase-contrast microscope converts these unnoticed phase changes into differences in brightness, which the human eye sees very well. The darker and lighter parts of the specimen make it very visible.This also works on reflected light microscopes.
Can view live samples and observe motility and responses to stimuli
A phase microscope is used to enhance the contrast of transparent or semi-transparent specimens by exploiting variations in refractive index. It allows for visualization of details that may be difficult to see with a standard brightfield microscope, making it useful for observing living cells and tissues.
A phase contrast microscope is used when observing transparent, unstained biological specimens, such as living cells or tissues, that lack significant color contrast. This type of microscope enhances the contrast of phase shifts in light passing through specimens, making it easier to visualize structures like cell organelles and membranes. It is particularly useful in cell biology and microbiology for studying live cells in their natural state without the need for staining, which can alter their behavior.
Frits Zernike invented the phase-contrast microscope in the 1930s, and he was awarded the Nobel Prize in Physics in 1953 for his contribution. This type of microscope allows for the visualization of transparent specimens that would normally be difficult to see using traditional bright-field microscopy techniques.
The microscope that takes advantage of differences in the refractive indexes of cell structure is the phase contrast microscope. The microscope that is used to see internal structure of cells in a natural state is also a phase contrast microscope.