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The Microscope: A Gateway to the Invisible World
- 1. Microscope PRESENTED BY: RAGINIM. THOMARE PRESENTED TO: MRS. MANSI
- 2. CONTENTS 1. Introduction 5. Optical Components 2.Historical Background 6. Mechanical Components 9. Light Microscope 10. Electron Microscopes 3. Principle of Microscopy 7. Illumination System 11. Fluorescence Microscope 4. Basic Components of a Microscope 8. Types of Microscopes (Overview) 12. Confocal Laser Scanning Microscope
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- 4. Introduction • A MICROSCOPE(GREEK: mikron = small and scopes = to look) • MICROSCOPE: Is an instrument for viewing objects that are too small to be seeen by the nakes or unaided eye. • MICROSCOPY: The science of investigating small objects using such an instrument is called microscopy.
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- 6. Historical Background 1590 Zacharias andHans Janssen (Netherlands) created the first compound microscope. 20th century Development of electron and fluorescence microscopes. 1665 Robert Hooke observed “cells” in cork using a light microscope. Today Advanced digital and atomic microscopes provide nanoscale imaging. 1674 Antonie van Leeuwenhoek improved lenses, discovering bacteria and protozoa.
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- 8. Principle of Microscopy Microscopyworks on two key principles: Magnification Enlarging the image of the specimen. Resolution The ability to distinguish two close objects as separate.
- 9. 04 Basic Components ofa Microscope
- 10. Basic Components of aMicroscope Optical Components Lenses for magnification. Mechanical Components Framework and focusing mechanism. Illumination System Provides and controls light.
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- 12. Optical Components Ocular (Eyepiece) 10× or15× magnificatio n. Diaphragm Adjusts light intensity. Objective Lenses Usually 4×, 10×, 40×, 100×. Condense r Mirror/Light Source Concentrate s light on specimen. Illuminates specimen.
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- 14. Mechanical Components Base Provides stability. Arm Connects base tohead. Stage Clips/Holde r Coarse & Fine Focus Knobs Keeps slide in place. Stage Holds specimen slide. Adjust image clarity. Body Tube & Revolving Nosepiece Holds lenses and allows rotation.
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- 16. Illumination System Light Source LEDor mirror for reflection. Iris Diaphragm Controls the light beam. Condenser Lens Focuses light on sample.
- 18. 08 Types of Microscopes(Overview)
- 19. Types of Microscopes (Overview) Light Microscope (Optical) Electron Microscope (TEM,SEM) Confocal Laser Scanning Microscope Atomic Force Microscope (AFM) Fluorescence Microscope
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- 21. Light Microscope Description Uses visible lightand glass lenses. Maximum Magnificati on Advantages ~2000×. Simple operation, low cost, can view living specimens. Resolution ~200 nm.
- 22. Working Principle (LightMicroscope) Light passes through condenser specimen objective lens eyepiece. Each lens enlarges the → → → image. The final image is inverted and magnified multiple times. Formula: Total Magnification = Objective × Eyepiece
- 23. TYPES OF LIGHT MICROSCOPE •SIMPLE MICROSCOPE • COMPOUND MICROSCOPE 1. BRIGHT FIELD MICROSCOPE 2. DARK FIELD MICROSCOPE 3. PHASE CONTRAST MICROSCOPE 4. POLARIZING MICROSCOPE
- 24. 1. Bright-field Microscope: •It uses visible light transmitted through the specimen. • The background appears bright (white) and the specimen appears dark. 2. Dark-field Microscope: • Only light scattered by the specimen enters the objective lens, making the specimen appear bright on a dark background.
- 25. 3. Phase-Contrast Microscope: •Converts differences in refractive index (optical density) of transparent specimens into differences in light intensity. • Uses a phase plate and annular diaphragm to create contrast without staining. • Allows viewing of living cells without killing them. 4. Polarizing Microscope: • Works on the phenomenon of polarized light. • Produces colored, high-contrast images depending on specimen composition.
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- 27. Electron Microscopes Description Use electronbeams instead of light. Require vacuum environment. Resolution Much higher (<1 nm).
- 28. TYPES • Transmission ElectronMicroscope (TEM): Electrons pass through thin specimen; internal details visible; magnification up to 2 million×. • Scanning Electron Microscope (SEM): Scans surface with electron beam; produces 3D surface images.
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- 30. Fluorescence Microscope Description Uses fluorescentdyes and UV light; excited molecules emit light of a longer wavelength. Applications Used in cell biology, immunology, and genetics to visualize labeled proteins or DNA.
- 31. 12 Confocal Laser ScanningMicroscope
- 32. Confocal Laser Scanning Microscope Description Useslaser beams and optical sectioning to produce 3D images. Advantages Excellent depth resolution; allows scanning of thick specimens such as tissues or organoids.
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- 34. Atomic Force Microscope (AFM) Description Anon-optical microscope; uses a sharp probe that scans the surface atom by atom. Resolution Up to 0.1 nm. Applications Used in nanotechnology, material science, and biophysics.
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- 36. Microscope Type Source Max Magnificatio n Resolution Specimen State MainUse Light Light 2000× 200 nm Living/Dead Cells, tissues TEM Electrons 2,000,000× <1 nm Dead Cell ultrastructu re SEM Electrons 1,000,000× ~5 nm Dead Surface imaging Fluorescenc e UV Light 1500× 180 nm Stained Proteins, DNA Confocal Laser 2000× 150 nm Fixed 3D imaging Comparison Table
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- 38. Applications of Microscopy Biology Cell study, tissueanalysis. Medicine Diagnosing diseases, histopathology . Materials Science Surface defects, metals, nanostructure Education Forensics Student training and research. Hair, fiber, and trace evidence. Pharmaceu ticals Drug testing and purity analysis.
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- 40. Advantages & Limitations Advantages •Enables discovery of microorganisms. • Supports diagnostic medicine. • Foundation of molecular and cellular biology. Limitations • Light microscopes are limited by wavelength. • Electron microscopes require complex sample preparation and vacuum. • Fluorescence may cause photobleaching.
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- 42. Safety & Care Handlewith care by holding the arm and base. Avoid touching lenses with fingers. Clean lenses with lens paper only. Always start focusing with the lowest power objective.
- 43. Summary Microscopes are keyto understanding the invisible world. From light to atomic microscopes, technology continues to evolve. Each type offers unique insights for different scientific fields.
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- 45. References Alberts, B. etal. (2022). Molecular Biology of the Cell, 7th Ed. Garland Science. NCBI – “Microscopy Techniques Overview.” Karp, G. (2021). Cell and Molecular Biology: Concepts and Experiments. Wiley. Encyclopaedia Britannica (2024). “Microscope.” Slayter, E.M. & Slayter, H.S. (2019). Light and Electron Microscopy. Cambridge University Press. Oxford Reference (2023). Oxford Dictionary of Biology.
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