Bioassay: The Quantal Response Assay

In many instances of interest in medical and biological research, the properties, activity or potency of certain substances cannot be measured directly by common in vitro chemical or physical methods, but can be measured quantitated only in terms of some effect they evoke in a living test subject, animal, plant or microorganism. Substances in this category include many hormones, vitamins, pharmacologically and toxicologically active substances, antibiotics, and immunologically active substances, vaccines, toxins, toxoids, antisera, allergens, etc. Measurement or quantitative assessment of the activity of such substances constitutes the subject matter of biological assay. Design of bioassay experiments and statistical analysis of the resultant data involve mainly an extension of principles and procedures readily available in standard-references on experimental design and statistical analysis with major emphasis on regression analysis and analysis of variance with or without transformation of the data originally recorded in conventional units.