Electronic labels consist of an electronic chip and an antenna assembled on a flexible support. In accordance with a preferred embodiment, saccharide compositions having a plurality of saccharide units are prepared by appending the saccharide units in iterative fashion to acceptor moieties which are themselves saccharide compositions prepared in accordance with this invention. Also provided is a method of purifying nucleic acid by applying a nucleic acid sample to a substrate having an anionic detergent affixed to a matrix, the substrate physically capturing the nucleic acid, bonding the nucleic acid to a substrate and generating a signal when the nucleic acid bonds to the substrate indicating the presence of the nucleic acid. Hooks are formed on the edges and positioned so as to be opened directly at each other in the closed position. The couple core portion 24 is joined to the internal core portion 22 and forms the remaining part of the closed magnetic path. In one approach, the method, system and computer program product modify a query for retrieving an entry from a directory information system, that is stored in a relational database, to retrieve the entry and a knowledge referral.