Phase Contrast Microscopy – Optical Components, Working Principle and Applications (Short Notes with PPT)


Applications of phase contrast microscope

Phase Contrast Microscopy
(Optical Components, Working Principle and Applications of Phase Contrast Microscope)

Working Principle of an Ordinary Microscope:

contrast in light microscopyIn an ordinary microscope, the object is viewed due to differences in colour intensities of the specimen. To create the colour intensities, the specimen is first stained with suitable dyes which will impart specific colour. In an ordinary microscope, the contrast is obtained when the light rays pass through a stained specimen because different stains absorb different amounts of light. These differential absorption properties of stained specimen modify the intensity or amplitude of the light waves transmitted by different regions of the cells and this ultimately creates contrast in the image. Thus, staining is essential to create contrast in an ordinary microscope. Moreover, the unstained specimen cannot be observed through an ordinary microscope.

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Why Phase Contrast Microscope?

The Phase Contrast Microscope is used to visualize unstained living cells. Most of the stains or staining procedures will kill the cells.  Phase contrast microscopy enables the visualization of living cells and life events.

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Properties and Characteristics of Alpha Particles, Beta Particles and Gamma Rays


Properties alpha, beta and gamma rays

Properties of Alpha Rays, Beta Rays and Gamma Rays

Unstable atoms on radioactive decay emit particles such as alpha particles, beta particles and gamma rays. These are energy particles, and by producing these energy-rich particles the unstable radioactive atom tries to attain atomic stability. The present post discusses the chemical, physical and biological characteristics of alpha, beta and gamma particles.

Compare alpha, beta and gamma rays

image source: wikipedia

Alpha Particles

Ø  They are also called alpha rays, designated as α2+.

Ø  Alpha rays consist of two protons and two neutrons bound tougher into particles.

Ø  They are identical to the helium nucleus.

Ø  They are produced by the alpha decay of radioactive materials.

Ø  They are positively charged particles.

Ø  Contain 2 positive charges.

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Difference between Alpha, Beta and Gamma Rays – Comparison Table


Difference between Alpha and Beta particles

Alpha Rays vs Beta Rays vs Gamma Rays
(Compare Alpha Particles, Beta Particles and Gamma Rays – Table)

An unstable atomic nuclei loss its energy by emitting radiations such as alpha rays, beta rays and gamma rays by a process called radioactive decay. A substance with such an unstable nucleus is called the radioactive substance. The particles produced by radioactive decay, i.e., alpha particles, beta particles and gamma rays are considerably different with distinct physical, chemical and biological properties.

Alpha rays: They are also called alpha particles. Alpha rays consist of two protons and two neutrons bound tougher into particles. It is identical to the helium nucleus. Alpha particles are produced as a result of the alpha decay of a radioactive material such as Uranium-238.

Beta rays: They are also called beta particles. Beta rays are high energy high and speed electrons emitted from a radioactive material after the beta decay. Potassium-40 is a beta emitter.

Compare alpha, beta and gamma rays

image source: wikipedia

Gamma rays: They are also called gamma radiations. Gamma radiations are electromagnetic radiations with high energy and high penetration capacity produced from a radioactive material after the gamma decay. Radium-226 is a gamma emitter.

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Difference between GM Counter and Proportional Counter


GM Counter vs Proportional Counter

Proportional Counter vs GM Counter
(Difference between Proportional Counter and GM Counter)

Proportional counter and GM counters are devices to detect and quantify radiations. The proportional counter is able to detect the energy of incident radiation and produce an output proportional to the intensity of the radiation. A GM counter detects ionizing radiation such as alpha particles, beta particles and gamma rays using the ionization effect produced in a Geiger–Müller tube. Both the instruments can quantify the intensity of radiation and have immense application in research, medicine and nuclear industry. The present post discusses the differences between a Proportional counter and a GM counter with a comparison table.

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Difference between GM Counter and Scintillation Counter


GM Counter vs Scintillation Counter

GM Counter vs Scintillation Counter
(Similarities and Differences between GM Counter and Scintillation Counter)

Geiger–Müller or GM Counter and Scintillation Counter are two commonly used devices to detect and quantify the radiation. The GM counter can detect all kinds of radiations such as alpha, beta and gamma rays, whereas the scintillation counter can detect only ionizing radiations. There are considerable differences in the working principle and applicability of GM counter and the Scintillation counter. The present post discusses the difference between G.M. Counter and Scintillation counter with a comparison table.

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