The Human Parvovirus B19 is the agent of several disease states: erythema contagiosum, a transient arthritis, and aplastic crisis in sickle cell anemia patients, and hydrops fetalis (a usually fatal outcome of pregnan- cy). B19 cannot be cultured using conventional techniques and antigen is difficult to collect from patients. As a result, commercial development of serological tests for the diagnosis of B19 infections has not been pos- sible. The intent of the proposed research is to develop synthetic peptides which can be used as capture antigens in ELISA-based immunodiag- nostic tests. To achieve this end, hexapeptide synthesis and epitope screening techniques will be used. Epitopes that significantly react with disease state sera will be used in the development of a prototype ELISA. This project will lead directly to Phase II clinical evaluations and thence to Phase III marketing.