This award will support continued maintenance and distribution of the protozoa collection housed at the Protistology Department of the American Type Culture Collection. The current holdings, all maintained in the cryopreserved state, consist of approximately 1,000 strains. NSF support contributes to the free-living protozoa portion of the Collection. In 1989, 3,010 protozoa were distributed, of which over 80% of requests came from the U.S. institutions. The user's community consists of Universities (48.7%), High Schools (1.4%), Hospitals (6.4%), For-Profit Organizations (31.1%), and Government (7.4%). The NSF support is primarily to provide research resources to the research community of the Biological, Behavioral and Social Sciences Directorate.