Definition: Organisms or complex pharmaceutical substances, preparations, or agents of organic origin, usually obtained by biological methods or assay. Biological agents are differentiated from BIOLOGICAL FACTORS in that the latter are compounds with biological or physiological activity made by living organisms. (From Webster's 3d ed).
differentiate from BIOLOGICAL FACTORS; /ther use: coordinate with disease /drug ther
calfactant [ Infasurf ] Infasurf is tradename; a lung surfactant extract from new born calves containing 35 mg/mL phospholipid & 2% surfactant-associated proteins B & C (wt/wt)