Speedy Way to Identify Novel Proteins

Novel protein molecules can be identified in days rather than months using a new method that relies on microscopic droplets of water suspended inside oil droplets.

The method uses a type of emulsion called WOW, for water-oil-water, and is modeled on living cells, which employ a fatty membrane to keep the inside and outside environments separate. The oily layer surrounding each miniscule water droplet acts as a barrier keeping genes, proteins, and other materials contained. Confining tests within a cell-like bubble enabled scientists to use a well-known method for analyzing living cells. The method involves a fluorescent marker that lights up when activated by the right protein and sorts through the cells for those containing marked proteins and their coding genes. Automated devices for sorting cells handle thousands of droplets per second.

The method was developed by Professor Shlomo Magdassi of the Hebrew University's Institute of Chemistry (Jerusalem, Israel) and Dr. Dan Tawfik and Amir Aharoni of the Weizmann Institute of Science and Technology (Rehovot, Israel) with support from the Israel Ministry of Science and Technology. Using their system, a large number of tests can be performed at once.

To demonstrate the efficiency of the system, the team isolated a new enzyme from a gene that was artificially mutated to produce random variations. They generated the enzymes in the droplets and sorted them according to those that were better at cleaving a specific enzyme in the bloodstream. The results from a screen completed in one afternoon were equivalent to those previously obtained through several rounds of mutation and screening--a process that would have taken several months.



Related Links:
Hebrew University's Institute of Chemistry
Weizmann Institute of Science and Technology