We have developed a relational laboratory database system, adapted to the daily book-keeping needs of laboratories that must keep track of information acquired on hundreds or thousands of clones in an effective and user-friendly fashion. Data, whether final or related to experiments in progress, can be accessed in many different ways, e.g. by clone name, by gene, by experiment or through DNA sequence. Updating, import and export of results is made easier by specially developed tools. This system, in network version, serves several groups in our Institute and (over the Internet) elsewhere, and is instrumental in collaborative studies based on expression profiling. It can be used in many similar situations involving progressiveaccumulation of information on sets of clones or related objects.