About this video

• Video Title: Cell Structure - Microscopy
• Channel: BIALIGY.com
• Speakers: None explicitly mentioned.
• Duration: 00:11:53

Overview

This video explains the fundamental principles and types of microscopy used to study cell structure. It covers the three key features of microscopy: magnification, resolution, and contrast, and then details the characteristics, advantages, and disadvantages of light microscopes and electron microscopes (TEM and SEM).

Key takeaways

• Microscopy Fundamentals: Microscopy relies on three main features: magnification (the ratio of image size to actual size), resolution (the measure of image clarity, dependent on the wavelength of radiation), and contrast (making structures stand out, often through staining).
• Light Microscopes: These use visible light, passing it through an object, which causes light to bend, leading to magnification. They typically offer about 1,000x magnification and have a resolution of about two micrometers. A limitation is their inability to reveal much about internal cell structures.
• Electron Microscopes: These utilize a beam of electrons for magnification, offering much higher magnification (up to 250,000x) and resolution than light microscopes, allowing for the visualization of internal structures.
• Types of Electron Microscopes:
  • Transmission Electron Microscope (TEM): Electrons pass through a specimen, often embedded in plastic.
  • Scanning Electron Microscope (SEM): Electrons interact with a specimen coated in gold film, producing a 3D image. SEM is often preferred for its detailed 3D visualization.
• Limitations of Electron Microscopes: Electron microscopy is an invasive process that kills cells, can alter structure, is expensive, and requires significant preparation.