Electron Microscopy: Bringing Color to the Nanoworld
Introduction
Electron microscopes are powerful tools that allow scientists to see objects at the nanoscale. However, traditional electron microscopes produce black and white images, which can make it difficult to distinguish between different cellular structures.
Researchers at the University of California, San Diego, have developed a new technique that adds artificial color to electron microscope images. This technique could help scientists better understand the structures and functions within cells.
How the Technique Works
The new technique combines light microscopy and electron microscopy. First, scientists use a light microscope to identify the structures they want to highlight. Then, they introduce a small amount of rare earth metal to the structures.
Next, they subject the sample to an electron microscope. The electron microscope fires electrons at the tissue. Some electrons go right through, while others hit thicker or heavier materials and bounce back.
A few electrons strike the rare earth metal and displace an electron there. This causes the displaced electron to fly out, along with a little bit of energy. The energy is distinct to the particular metal used, and this is what the microscope measures. This technique is called electron energy loss spectroscopy.
Applications of the Technique
Scientists have used the new technique to image cell structures like the Golgi complex, proteins on the plasma membrane, and even proteins at the synapses in the brain.
The technique could be used to study a wide range of biological processes, including:
- The localization of proteins within cells
- The interactions between different cellular structures
- The development and progression of diseases
Benefits of the Technique
The new technique offers several benefits over traditional electron microscopy:
- Color images: The technique adds artificial color to electron microscope images, which makes it easier to distinguish between different cellular structures.
- High resolution: The technique provides high-resolution images, which allows scientists to see objects at the nanoscale.
- Versatility: The technique can be used to image a wide range of biological samples.
Comparison to Other Techniques
There are other techniques that can be used to provide color imagery from electron microscopes. However, these techniques have their own limitations.
- Correlative light electron microscopy: This technique requires two different images, from different microscopes, which can reduce precision.
- Immunogold labeling: This technique can give unclear staining.
The Legacy of Roger Tsien
The paper describing the new technique was the last to bear the name of Roger Tsien, a Nobel prize-winning chemist who died in August. Tsien was best known for using a fluorescent protein from jellyfish to illuminate cellular structures.
The new technique is a testament to Tsien’s legacy of innovation in microscopy. It is a powerful tool that could help scientists better understand the world at the nanoscale.
Conclusion
The new technique for adding artificial color to electron microscope images is a significant advance in microscopy. It could help scientists better understand the structures and functions within cells, and could lead to new insights into a wide range of biological processes.
