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
bifidobacterin [ bifidumbacterin,bifidumbacterin-forte ] a probiotic from a culture of Bacillus bifidum; a lypholized biopreparation immobilized on special activated charcoal