The DCT, NCI, is engaged in the discovery and development of new substances with potential as antitumor agents. The search for new substances includes both synthetic and naturally occurring compounds of diverse structure. Developmental activities include preparation of significant quantities, analysis of these substances, and development and production of injectable pharmaceutical dosage forms. Further development and evaluation of these substances in larger animals and ultimately in man requires characterization of these agents. Suitable qualitative and quantitative methods must be developed to ascertain the purity and quality of this material from batch to batch in both bulk form and pharmaceutical dosage forms. About two or three compounds will require characterization annually. Most compounds will be proteinaceous and may include largomycin, interferon, lentanin, etc.