The chemistry of life is different from chemistry at large, in part because it takes place in tiny containers called cells.
So chemists at Stanford University, working with researchers at the University of Göteborg in Sweden and Pomona College in Claremont, Calif., have found a way to make tiny, cell-sized containers, called vesicles, and use them to study the chemical reactions of biological molecules in an environment that closely mimics the interior of a living cell.
"We now have the world's smallest test tubes," says Richard N. Zare, the Marguerite Blake Wilbur Professor of Chemistry at Stanford, who headed the research effort reported in the March 19 issue of the journal Science. The ability to study chemical reactions in cell-like containers has a number of possible applications. Among them are:
"In the past, when studying the chemistry of life, we had two basic choices: to experiment 'in vivo' -- in living cells -- or 'in vitro' -- in glass containers. Now we have a third choice, that is in-between the two, but much closer to 'in vivo,'" Zare says of the vesicle approach.
Producing this new form of micro-chemistry begins by creating tiny vesicles that
contain a single chemical compound. The researchers found that they can reliably
create these membrane sacs in a few minutes. They do so by floating a layer of
artificial membrane on the surface of a mixture of a desired chemical and a
suitable solvent, such as a mixture of alcohol and water, and then causing the
solvent to boil away by lowering the air pressure above the membrane. As the
water evaporates, it leaves behind vesicles filled with the desired chemical
that range in size from 50 microns to 50 nanometers in
Contact: David F. Salisbury