Transmission Electron Microscope (TEM) is an advanced analytical instrument used to visualize the internal structure of specimens. It uses highly energetic beam of electrons instead of light. It works under high vacuum condition. The electron gun produces electron beam. This beam is then focused and guided by a series of electromagnetic lenses. The specimen used … Read more
Scanning Electron Microscope (SEM) is an advanced magnifying instrument that is used to observe the surface of a sample by using focused beam of accelerated electrons. It does not use visible light for image formation. It uses electron beam because electrons have much shorter wavelength than light photons. So, SEM can produce image with very … Read more
Phase contrast microscope is an optical microscope that is used to observe transparent and unstained living cells. It converts small phase changes of light into visible contrast. These phase changes are produced when light passes through the different parts of the specimen. It was developed by Frits Zernike in 1930s. This microscope is very useful … Read more
Confocal Microscope is an advanced optical microscope that is used to produce clear and sharp image by removing the out-of-focus light. It uses laser light to focus on a single point of the specimen. It gives better resolution and contrast than the ordinary light microscope. In confocal microscope, the light is not passed through the … Read more
Stereo microscope is an optical microscope that is used to observe large, three dimensional and opaque specimens at low magnification. It is also called dissecting microscope. It gives a magnified image of the surface of the object by using reflected light. It is different from compound microscope because compound microscope uses transmitted light through thin … Read more
Microscope is an instrument that is used in science laboratories to visualize very minute objects, such as cells and microorganisms. It gives a contrasting image that is magnified, so the structures can be observed. The term microscope is derived from Greek words “mikrós” meaning “small” and “skópéō” meaning “look at”. Microscopes are made up of … Read more
Electron microscope is a high power microscope that uses a beam of accelerated electrons instead of visible light for illumination and image formation. Due to very short wavelength of electrons, it can overcome the diffraction limit of light microscope lenses. Hence, it gives very high resolving power and very high magnification as compared to compound … Read more
What is Cell Cycle? Cell cycle is the ordered sequence of events by which a cell grows and divides to form two genetically identical daughter cells. It is the process that ensures continuity of life by producing new cells from pre existing cells. The cell cycle is a carefully regulated process and it occurs in … Read more
What is Checkpoint? A checkpoint is a control point in cell cycle. It is a internal surveillance mechanism present in eukaryotic cell. It ensures that cell division occurs in proper manner. It act like a quality control step where progression is checked before moving to next phase. It is the process where cell checks cell … Read more
Paul Ehrlich Paul Ehrlich (1854–1915) was a German physician, biochemist and scientist. He is regarded as one of the founders of modern hematology, immunology and chemotherapy. His work was mainly concerned with immunity, staining techniques and chemical treatment of diseases. In 1908, he was awarded the Nobel Prize in Physiology or Medicine along with Élie … Read more
