Table 2-8. COMPARISON OF HORMONAL ASSAY SYSTEMS (versus RIA)

Assay		Binding Component		Advantage		Disadvantage(s)

Bioassay		innate receptor			biological			lacks practicality, precision, and sensitivity
Protein-binding	nonimmune carrier			no immunization		lacks specificity
RRA		isolated receptor			biological			lacks practicality
EIA		antibody				no radioactivity		lacks sensitivity, must add substrate
SPA		antibody, receptor			no separation step		patented technology
IRMA		antibody				short incubation		requires two antibodies
ELISA		antibody				no radioactivity		same as EIA and IMRA (sandwich)