Microscale techniques flourishing: New methods allow accurate cell current measurements, synthesis of proteins newly isolated from living cells, rapid screening of pathogens

When it comes to devising new techniques, small is definitely beautiful. This dictum is being proved again in several research fields, including electrochemistry and physiology, where currents through single channels in cellular membranes now can be measured accurately; in biochemistry, where combined technologies are permitting synthesis of practically any protein, provided that minute amounts of it can be obtained from living cells; and in bacteriology, where recombinant DNA methods soon may allow for a much more rapid screening and identification of pathogenic organisms than now is possible. Erwin Meher, Bert Sakmann, and their colleagues at Max Planck Institute for Biophysical Chemistry in Gottingen, West Germany, recently have refined a method for measuring currents through single ion channels in cell membranes. Currents in the range of a few picoamperes lasting for little more than several milliseconds now can be measured routinely, Meher says. "The key parameter is how well you can establish contac...