Immunoassays

Types of Immunoassays

• Enzyme-linked immunosorbent assay (ELISA)
• Enzyme multiplied immunoassayu technique (EMIT)
• Enzyme immunoassay (EIA)
• Radioimmunoassay (RIA)
• Immunoradiometric assay (IRMA)
• Microparticle enzyme immunoassay (MEIA)
• Radi
• FIA

Assay	Labelled Molecule	Competitive or Non-competitive	Homogeneous or Heterogenous	Advantages	Disadvantages
ELISA (Direct)	Ab	Non-competitive	Heterogenous
ELISA (Indirect)	Ag	Competitive	Heterogenous?
EIA
EMIT			Homogenous
RIA	Ag	Competitive	Heterogenous		☢
IRMA	Ab	Non-competitive	Heterogenous		☢
MEIA

Separation Methods

• Precipitation
  • Chemical
  • Immunological
• Phase adsoprtion
  • Liquid-phase adsoroption
  • Solid-phase adsorption
• Differential migration
  • Column separation (ion exchange by charge, gel filtration via size exclusion)
  • Centrifugation
  • Electrophoresis