Sophisticated network-based informatics support will increasingly be required for collaborating biomedical laboratories located in different geographic locations, both to accommodate the massive amount of data being generated in certain fields, and to allow different types of data produced at different laboratories to be analyzed in an integrated fashion. The paper describes the experience of the Yale Center for Medical Informatics in providing informatics support for collaborative projects in gene mapping (as part of the national Human Genome Project) and neuroscience (as part of the national Human Brain Project). The paper describes the informatics needs of the two projects and the solutions being developed, describes certain lessons learned, and discusses certain broader issues that arise.