But some labs had difficulty using the electric field method. About half of them got it to work, but others had problems with the electric voltage causing tissue damage, the researchers said.
Now, Deisseroth and his colleagues have developed a method of pulling out the fat using chemicals and a warm bath, called "passive CLARITY." The new method takes a little longer than the original one, but is much easier to do and removes all the fat without damaging the tissue, the researchers said.
Many scientists have started using CLARITY to image donated postmortem brains from people with diseases such as autism or epilepsy, to understand them and discover potential treatments. The new, passive method minimizes any risk of damaging these valuable clinical samples, the researchers said.
Next, Deisseroth and his team addressed the problem of microscopy methods. Often, scientists will use colorful probes to stain a tissue or type of cell in the brain, which makes it glow green, blue or some other color when certain types of light are shone on it. With CLARITY, these colors can shine through the whole brain.
The problem is, these probes get bleached and stop working after being exposed to too much light. Scientists usually image the brain point-by-point, so producing an image of an entire brain takes longer than the probes normally last.
To get around the issue, Deisseroth's team adapted a technique known as light sheet microscopy, in which an entire plane of tissue can be scanned at a time. Using this technique, researchers should be able to image whole brains without the probes getting bleached, the researchers said. Deisseroth's lab provides free training courses on how to use the CLARITY technique.
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Inside the Brain: A Photo Journey Through Time 5 Crazy Technologies That Are Revolutionizing Biotech 3D Images: Exploring the Human Brain Original article on Live Science. Copyright 2014 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.