Researchers at MIT have created a new chemical process called ELAST that is used to make tissue used in a laboratory setting stretchable, compressible, and nearly indestructible. It’s been a challenge in biomedical research labs around the world to make imaging cells and molecules in the brain and other large tissues easier while making the samples tough enough to last for years of handling in the lab. The team’s new chemical ELAST process is an answer to that challenge.
MIT researchers say that their process provides scientists with a speedy way to fluorescently labeled cells, proteins, genetic material, and other molecules within the brain, kidney, lung, heart, and other organs. The new process allows the tissues to be stretched out or squished down into very thin sections allowing labeling probes to infuse into them far more rapidly.
Demonstrations show that after repeated expansions or compression to speed up labeling, the tissues can snap back to the original unaltered form except for the new labels. ELAST was developed amid work on a five-year project to make the most comprehensive map of the entire human brain. This process requires being able to label and scan every fine cellular and molecular detail in the thickest slabs possible to preserve the 3D structure.
It also means the labs have to be able to keep samples perfectly intact for years, even as they must accomplish numerous individual rounds of labeling quickly and efficiently. Each round of labeling could include a specific type of neuron one day or key protein the next, telling scientists something new about how the brain is structured and works.
The engineering efforts for the material came down to finding the right formulation of a gel-like chemical called polyacrylamide. When the formula infuses the tissue, it results in the entanglement of long polymer chains with links that can slip around, giving the tissue structural integrity but with much more flexibility. Cells and molecules of the tissue become entangled with the long polymer chains adding to the ability of the tissue to withstand stretching or squashing without anything becoming torn or permanently displaced in the process.