Scientists have turned a mouse transparent by pumping detergent through its veins, an advance that will allow them to see the rodent's body and brain in unprecedented detail.
The problem with making any living tissue transparent is lipids, a class of molecules that includes fats and cholesterol, which block light from passing through tissues.
Last year, neuroscientists at Stanford University found a way to replace the lipids in a mouse brain with a transparent hydrogel called acrylamide.
The brain was bathed in acrylamide and then placed in detergent, which slowly dissolves the lipids over time. An electric field speeds up the process.
However, acrylamide can't penetrate every corner of a whole mouse and an electric field can damage tissue with heat.
Viviana Gradinaru of the California Institute of Technology in Pasadena and her team tried a different technique: they took a dead mouse and pumped detergent through its circulatory system, according to 'Gizmodo'.
Gradinaru's team was able to render peripheral organs transparent within two days and a whole mouse transparent within two weeks.
The team then removed any large bones that might be blocking the view of certain cells, injected fluorescent chemicals into the animal to highlight specific cells, such as kidney or intestinal cells, and visualised those cells using microscopes.
They could clearly map the microscopic structures of the body and brain.
"Now we are working on mapping the nervous system," Gradinaru told 'New Scientist'.
Working out exactly where nerves start and stop may help inform treatments that work by stimulating the nervous system, she said.
