Advances in Microscopy

What is the primary application of Immunofluorescence?

What is the purpose of etching in Freeze-Fracture Electron Microscopy?

What is the primary advantage of Cryogenic Electron Microscopy?

What is the purpose of a computer algorithm in Cryogenic Electron Microscopy?

What is the primary limitation of Immunofluorescence?

What is the primary difference between Freeze-Fracture Electron Microscopy and Cryogenic Electron Microscopy?

What was the limitation of using compound light microscopes beyond a certain magnification?

What is the main advantage of using Electron Microscopes over Compound Light Microscopes?

What is the purpose of using Fluorescent Stains in microscopy?

What is the drawback of using Electron Microscopes?

What did the development of microscopes allow for?

Why do most cell parts need to be stained in microscopy?

Developments in Microscopy

Microscopes were first invented in the 17th century, allowing for the discovery of cells.
As microscopes improved, our understanding of cells and tissues improved dramatically.

Compound Light Microscopes

Allowed for the discovery of bacteria, chromosomes, mitosis, and meiosis.
Limited to magnifications of 400X, beyond which it becomes harder to produce a focused image.

Electron Microscopes

Use beams of electrons to produce high-resolution images.
Can magnify objects up to 1,000,000X their original size.
Drawbacks: cannot produce color images, and cells need to be dead to examine them.

Fluorescent Stains

Use intense light sources (lasers, high power LED) to produce bright images.
The light is absorbed by the sample and re-emitted, generating high-resolution images.
Most cell parts are white or colorless and need to be stained to be visible.

Immunofluorescence

An advancement in fluorescent staining that uses antibodies to bind to specific chemicals (antigens) in the sample.
Produces multi-colored fluorescent images showing where different chemicals are located.

Freeze-Fracture Electron Microscopy

Produces images of surfaces within cells.
A cell is rapidly frozen, fractured, and then etched to enhance the texture.
A replica is taken of the fracture and can be examined with an electron microscope.
Best for showing the texture of a cell part.

Cryogenic Electron Microscopy

Typically used to research the structure of proteins.
A protein solution is flash frozen and analyzed with an electron microscope.
A computer algorithm analyzes the different patterns and generates a 3D image of the protein structure.

Explore the history and improvements of microscopes, from their invention in the 17th century to their current capabilities, and how they have expanded our understanding of cells and tissues.