Multiplex cytokine assays are immunoassays that can detect numerous cytokines simultaneously. They evaluate cytokines secreted by immune cells in biological pathways and assess experimental therapies’ efficacy. Some panels see multiple cytokines, such as interferon (IFN) subtypes, CC chemokines, CXC chemokines, and interleukins (ILs). Other boards identify cytokines generated by specific cells, such as Th1 or Th2. Serum, cell culture supernatants, and other body fluids can be used as samples for the experiments.
Multiplex assays, as opposed to standard ELISAs, may detect many analytes from a single sample simultaneously, saving time, effort, money, and valuable sample material. Cytokine multiplex test kits are handy in clinical settings. On a broad scale, protein microarrays investigate cytokines’ interaction, function, and activity. This sensitive, high-throughput approach allows for the simultaneous measurement of many cytokines.
There are primarily two methods:
ELISA
Yalow and Berson described radioimmunoassay (RIA) in 1959, for which they received the 1997 Nobel Prize in Physiology or Medicine. In the 1970s, Enzyme-Linked ImmunoSorbent Assay (ELISA) was developed to hunt for alternative labels to replace radioactive isotopes. In a conventional double antibody sandwich ELISA, one antibody coupled to the bottom of a well offers antigen capture and immunological specificity. In contrast, another antibody linked to an enzyme provides detection and an amplification factor. This method allows for the precise and sensitive identification of the antigen or cytokine of interest. Because of these advantageous characteristics, ELISA has become the standard cytokine measuring method and is widely used in clinical laboratories and biomedical research.
There are ELISA kits available for commonly measured cytokines. The enzyme-linked immunosorbent assay (ELISA) is a simple, low-cost analytical method that offers the specificity and sensitivity needed for cytokine research in vitro or in vivo. The acronym ELISA stands for enzyme-linked immunoassay. It is a standard laboratory test for detecting antibodies in the blood. An antibody is a protein produced by the body’s immune system when it detects harmful substances called antigens.
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Luminex
The multiplex cytokine test format differs significantly from traditional ELISA in one crucial way: the multiplex capture antibody is connected to a bead, whereas the ELISA capture antibody is bonded to the microplate well. Luminex examination often begins with liquid biological materials such as serum/plasma, supernatants of cultivated cells, or activated whole blood. The method employs 5.6-micron magnetic microspheres that are internally colored with varying intensities of red and infrared fluorophores. Each bead is assigned a unique number, or bead area, allowing one dot to be distinguished from another. Beads are covalently linked to multiple antibodies that may be combined in the same test using a 96-well microplate format.
The Bio-Plex Array Reader reads dots in a single file using dual lasers for categorizing and quantifying each analyte. The Bio-Plex array reader is a flow cytometry-based equipment that uses fluidics, two lasers, four detectors, and real-time digital signal processing to discriminate between the 100 separate sets of color-coded microspheres containing an analyte-specific assay.