A streamlined method can screen large numbers of enzymes for those that have potential in manufacturing drugs and other useful compounds.

In conventional screening, candidate enzymes are put to work catalysing reactions. An analytical technique called mass spectrometry is then used to identify the reaction products, allowing researchers to determine whether the enzymes have the desired activity. But that method is difficult to use for complex mixtures of molecules because the mixture first needs to be painstakingly separated into its components.

Jay Keasling and Tristan de Rond at the University of California, Berkeley, and their colleagues have found a way to eliminate that separation step. The researchers used members of a common family of enzymes to produce a stew of new molecules. Next, they added a chemical tag that stuck to the new molecules and then placed the mixture on a surface with a special coating. When the researchers washed the surface, the tags adhered to the coating. The team then dislodged the tags and the attached molecules and placed them into a mass spectrometer for identification.

The researchers say that, with some adjustments, the method could be used to screen a wide variety of enzymes.