(Magnetic) Immunoassays

(Magnetic) Immunoassays


An immunoassay is a biochemical test that measures the presence or concentration of a macromolecule or a small molecule in a solution through the use of an antibody (usually) or an antigen (sometimes). The molecule detected by the immunoassay is often referred to as an "analyte" and is in many cases a protein, although it may be other kinds of molecules, of different size and types, as long as the proper antibodies that have the adequate properties for the assay are developed. Analytes in biological liquids such as serum or urine are frequently measured using immunoassays for medical and research purposes.

Magnetic particles can be used as a solid support phase in immunoassays. MagSi-STA are superparamagnetic silica beads with a surface coating of streptavidin for use with biotinylated antibodies.


Magnetic immunoassays (MIA) use magnetic beads as detection labels instead of conventional enzymes, fluorophores, or luminescent molecules. The presence of paramagnetic beads is detected by a reader which measures the magnetic response of the beads, induced by a magnetic field. The signal measured by the magnetometer is proportional to the concentration of the analyte.


MagSIGNAL are superparamagnetic beads with a mean diameter of 300 nm and are suitable for magnetic immunoassays in a variety of formats such as conventional lateral flow tests, microfluidic applications and biochips.