The crystal robot
 |
Biology's next great challenge is to learn the structure of the proteins specified by tens of thousands of newly sequenced genes. Crystallography is the basic method, but growing protein crystals, when it can be done at all, takes days or weeks.
The Bioinstrumentation Group devised a robot that does the work quickly and automatically. "The basic idea is that, instead of having to plod through all the hundreds of ways you might get a protein to crystallize, you more or less try 'em all at once," says Joe Jaklevic.
Once a protein has been chosen, 480 different variations of growth solution can be used simultaneously, each in its own tiny reservoir in a plastic cassette. By crystallizing a few nanoliters of protein instead of microliters, Jaklevic explains, "we see crystals within a few hours to a few days."
A camera can check the cassettes twice a day to detect the growth of tiny crystals in the transparent reservoirs; solutions that don't produce good results are rejected. When crystals appear, the reservoirs can be returned for a second cycle under conditions tuned for optimum growth.
More on the "crystal robot"
| A
breath of bad air In the mid-1970s, the Environmental Protection Agency asked Berkeley Lab engineers to come up with a rugged, dependable way to study particulate air pollutants. Joe Jaklevic and his colleagues built an analyzer that sucked in air, separated particles by size, and determined their composition using x-ray fluorescence: x-rays excite atoms in the samples, which re-emit x-rays characteristic of specific elements. The first model measured a range of elements, storing its samples on filters that fit into 35 mm slide-photo carousels. A two-year study in St. Louis established that coarse particles come mostly from sources like blowing dust, but more dangerous fine particles containing lead and sulfur come from vehicles and power plants—sulfur particles fine enough to inhale cause respiratory diseases. To measure sulfur alone, Jaklevic and his colleagues designed a single-channel analyzer that could store 800 samples on a roll of tape 100 feet long. Copied by industry, the air samplers became a standard method for studying urban environments. An x-ray analyzer built for EPA by Berkeley Lab proved so reliable that EPA used it daily for a quarter of a century — until it finally broke. Berkeley Lab engineers are now building a replacement. |
|
