The versatile laboratory multianalyte profiling (LabMAP™) system developed by Luminex Corp. of Austin, Texas, can be used for virtually any bioassay that is based on the specific binding of one molecule to another.1-3 Applications include assays for nucleic acids, antigen/antibody binding, receptor/ligand binding, and enzyme activity. LabMAP assays for enzyme activity can be based on the immunological detection of the product, or, in some cases, may follow the gain or loss of fluorescence (e.g., in protease-catalyzed cleavages of fluorescently labeled peptide targets). LabMAP assays employ three different fluorochromes: two to create color-coded microspheres, and the third for quantifying the reaction. Polystyrene microspheres are internally dyed with precise ratios of two spectrally distinct fluorochromes. This ratio confers a unique identifying "signature" or "spectral address" to each microsphere set.
Bioassays are conducted on the surfaces of the microspheres. Each capture probe (e.g., analyte-specific antibody or complementary oligonucleotide) is immobilized onto a color-coded ...
