Insect sting allergy to bees and vespids (hornets, yellowjackets & wasps) is common for a segment of our population. Allergic people vary in their antibody response to the different protein allergens in each venom. One aspect of the proposed research is to purify the venom proteins of different vespids so that their immunochemical properties can be studied. On the basis of the work which we have done, the purified proteins of different vespids can be more reliable reagents than the whole venoms are for unambiguous diagnosis of patients' sensitivity to vespids. This is of medical importance for proper immunotherapy of patients with the appropriate vespid venom(s). The purified venom proteins are also useful reagents for following the heterogeneity of antibody responses in patients on venom therapy. This may lead to a better understanding of the immunologic mechanism for successful venom immunotherapy. Another aspect of the proposed research is to delineate the antigenic determinants of two venom protein allergens of honey been venom, phospholipase A2 and melittin. The experimental approach is to use mouse monoclonal antibodies specific for these allergens as reagents for the detection and purification of antigenically active peptide fragments of these two proteins. Since antigenically active peptides may be of the approximate size of a hexapeptide, their sequences can be readily determined. This approach is in principle applicable to any protein without prior knowledge of its complete sequence. Therefore this approach, if proven feasible, should find wide applicability for studies of a variety of protein antigens of interest in the fields of allergy and infectious diseases.