Glucuronic acid is a common chemical moiety that decorates the xylan polymer of hemicellulose.  This chemical substituent impairs both enzymatic and acidic hydrolysis of xylosidic bonds.  The a-glucuronidase enzyme hydrolyzes the 1,2-linked glucuronic acid from the terminal, non-reducing xylose of xylo-oligosaccharides.  There are relatively few a-glucuronidase genes in the public databases.  We have developed an assay with commercially-available reagents that can be used to search DNA libraries for a-glucuronidase genes in a high throughput, solid phase activity screen.