Medical Research Council - London Institute of Medical Sciences

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Through a Phase

Mimicking cells using oil droplets shows how phase separation – which can go awry in disease – can be manipulated

11 March 2019

Through a Phase

Being in the right place at the right time often creates opportunities – even inside our cells. A meeting of molecules might cause a reaction, or movement, or total destruction. Made in a laboratory, these blobs mimic the natural crowds of molecules that come together spontaneously in many cells. A fluorescence microscope pictures a sticky protein called poly-L-lysine (artificially coloured yellow), and a cellular fuel source called adenosine triphosphate (ATP) trap strands of DNA (dark spots). Unlike our cells’ organelles, which have a membrane to keep their contents organised, these membrane-less droplets form and disband using phase separation, a bit like how droplets of oil separate in water. Differences in the DNA strands make these droplets more or less likely to form around them – which might help to understand how to manipulate phase separation, or reverse the cases where it goes awry in diseases like amyotrophic lateral sclerosis.

Written by John Ankers

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