Analysis of clinical and biological samples using microsphere-based multiplexing Luminex system.

Immunoassays are one of the most commonly used biomedical techniques to detect the expression of an antibody or an antigen in a test sample. Enzyme-linked immunosorbent assay (ELISA) has been used for various applications including diagnostic tools and quality controls. However, one of the main limitations of ELISA is its lack of multiplexing ability, so ELISA may not be an efficient diagnostic tool when a measurement of multiple determinants is needed for samples with limited quantity such as blood or biological samples from newborns or babies. Although similar to ELISA in assay measurement, Luminex is an xMAP-based technology that combines several different technologies to provide an efficient and accurate measurement of multiple analytes from a single sample. The multiplexing can be achieved because up to 100 distinct Luminex color-coded microsphere bead sets can be coated with a reagent specific to a particular bioassay, allowing the capture and detection of specific analytes from a sample. Various biological samples can be analyzed by a Luminex system include serum, plasma, tissue and cell lysate, saliva, sputum, and bronchoalveolar lavage (BAL). The most common Luminex-based assays are used to detect a combined set of cytokines to provide a measurement of cytokine expression profiling for a diagnostic purpose.