Phase Contrast Microscopy PPT by Easybiologyclas


Biophysical Instrumentation PPT

Phase Contrast Microscopy PPT

What is Phase Contrast Microscope? What are the limitations of ordinary light microscope? Who invented the phase contrast microscope? What is the working principle of phase contrast microscope? What are the optical components of phase contrast microscope? What is the importance of Annular Diaphragm and Phase Plate in phase contrast microscope? How contrast is created in phase contrast microscopy? What are the applications of phase contrast microscope? What are the limitations of phase contrast microscopy?

Learn more: Lecture Note in Phase Contrast Microscopy

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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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Difference between Lyophilic and Lyophobic Sols – Comparison Table


Compare Lyophilic and Lyophobic Sols

Lyophilic Sols vs Lyophobic Sols
(Difference between Lyophobic and Lyophilic Sols)

Sols are colloidal systems in which a solid is dispersed in a liquid. There are two types of sols – (1) Lyophobic Sols and (2). Lyophilic Sols

(1). Lyophilic sols:

They are solvent loving sols. In lyophilic sols, the dispersed phase shows a positive affinity for the dispersion medium (solvent). The high affinity of dispersed particles with the dispersed medium is due to the formation of a large number of hydrogen bonds.

(2). Lyophobic sols:

They are solvent hating sols. In lyophobic sols, the dispersed phase does not have any attraction for the dispersion medium.

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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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