Immunoassays

MSD multi-array technology is a type of immunoassay used to detect and quantify proteins or other biomolecules in biological samples. It is based on a sandwich immunoassay format, in which two antibodies are used to detect and measure the target molecule.

Fig. MSD technology principle. MULTI-SPOT technology enables multiplexing up to ten analytes per well and supports different assay formats including sandwich immunoassays. (Figure is adapted from www.mesoscale.com)

How it works:

• The sample is first added to a plate containing capture antibodies, which bind to the target molecule
• A detection antibody labeled with the ruthenium complex is then added, which binds to a different site on the target molecule
• After washing away unbound materials, a solution containing a reducing agent is added, causing the ruthenium complex to emit light
• The amount of light emitted is directly proportional to the amount of target biomolecule in the sample

The Luminex assay is a bead-based multiplex immunoassay that can simultaneously measure multiple analytes in a single sample. It utilizes color-coded microspheres, each with a unique spectral address, to capture and detect specific biomolecules.

How it works:

• Microspheres are first coated with capture antibodies specific to the analyte of interest
• The sample is then added to the microspheres, and the target biomolecules bind to their corresponding capture antibodies
• A biotinylated detection antibody specific to the analyte is then added, followed by a streptavidin-conjugated fluorophore
• The level of fluorescence is then measured for each microsphere, providing a quantitative measurement of the amount of analyte in the sample

Fig. Luminex^® Assay Principle: Luminex assays use a set of fluorescent beads where each bead falls in a unique spot on the fluorescent spectrum. The beads are coated with capture antibody targeted to the analyte of interest. (Figure is adapted from www.rndsystems.com)

The ELISpot assay is an immunoassay that measures the frequency of antigen-specific immune cells, such as T cells or B cells, by detecting the secretion of cytokines or antibodies. The assay is based on the principle of enzyme-linked immunosorbent assay (ELISA) and is commonly used in immunology research and clinical diagnostics.

How it works:

• A multi-well plate is coated with a capture antibody specific to the cytokine or antibody of interest
• Immune cells, such as T cells or B cells, are then added to the plate and stimulated with the antigen of interest. If the immune cells are specific to the antigen, they will secrete cytokines or antibodies, which will bind to the capture antibody on the plate
• A secondary detection antibody, conjugated to an enzyme such as alkaline phosphatase or horseradish peroxidase, is then added to the plate, which binds to the cytokines or antibodies
• A chromogenic substrate is then added, which reacts with the enzyme to produce a visible spot in the well. The number of spots is counted and correlates with the frequency of antigen-specific immune cells in the sample.

• Mouse Cytokine/Chemokine Universal Panel (32-plex) : G-CSF, GM-CSF, IFN-γ, IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-9, IL-10, IL-12 (p40), IL-12 (p70), IL-13, IL-15, IL-17, IP-10, KC, LIF, LIX, MCP-1, M-CSF, MIG, MIP-1α, MIP-1β, MIP-2, RANTES, TNF-α, VEGF, Eotaxin/CCL11
• Mouse TH17 Panel: CD40 Ligand, GM-CSF, IFN-γ, IL-1β, Il-2, IL-4, IL-5, IL-6, IL-10, IL-12 (p70), IL-13, IL-15, IL-17A, IL-17E/IL-25, IL-17F, IL-21, IL-22, IL-23, IL-27, IL-28B, IL-31, IL-33, MIP-3α/CCL20, TNF-α, TNF-β
• Mouse CD8⁺ T Cell Panel: sCD137, sFas, sFAS ligand, GM-CSF, Granzyme B, IFNγ, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, MIP-1β, RANTES, TNF-α
• Mouse High Sensitivity T Cell Panel: GM-CSF, IFNγ, IL-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-10, IL-12 (p70), IL-13, IL-17A, KC/CXCL1, LIX, MCP-1, MCP-2, TNF-α

• V-PLEX Proinflammatory Panel 1 Human Kit: IFN-γ, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, TNF-α
• V-PLEX Cytokine Panel 1 Human Kit: GM-CSF, IL-1α, IL-5, IL-7, IL-12/IL-23p40, IL-15, IL-16, IL-17A, TNF-β, VEGF-A
• V-PLEX Proinflammatory Panel I (4-Plex): IFN-γ, IL-1β, IL-6, TNF-α
• V-PLEX Chemokine Panel 1 Human Kit: MCP-1, MCP-4, Eotaxin, Eotaxin-3, IP-10, MDC, TARC, MIP-1α, MIP-1β, IL-8 (HA), IL-8
• V-PLEX Human Proinflammatory Panel II (4-Plex): IL-1β, IL-6, IL-8, TNF-α
• V-PLEX Th17 Panel 1 Human Kit: IL-17A, IL-21, IL-22, IL-23, IL-27, IL-31, MIP-3α

Cytokines:

• V-PLEX Proinflammatory Panel 1 NHP Kit: IFN-γ, IL-1β, IL-2, IL-6, IL-8, IL-10
• V-PLEX Cytokine Panel 1 NHP Kit: GM-CSF, IL-5, IL-7, IL-12/IL23p40, IL-15, IL-16, IL-17A, TNF-β, VEGF-A
• V-PLEX Chemokine Panel 1 NHP Kit: Eotaxin-3, MDC, IL-8, IL-8 (HA), IP-10, MIP-1α, MIP-1β, MCP-1, MCP-4, TARC
• V-PLEX NHP Cytokine 24-Plex Kit: Eotaxin-3, GM-CSF, IFN-γ, IL-1β, IL-2, IL-6, IL-7, IL-8, IL-8 (HA), IL-10, IL-12/IL23p40, IL-15, IL-16, IL-17A, IP-10, MCP-1, MCP-4, MDC, MIP-1α, MIP-1β, TARC, TNF-β, VEGF-A

Metabolic:

• V-PLEX GLP-1 Total Kit: GLP-1 (active)
• V-PLEX GLP-1 Active Kit: GLP-1 (total)

• V-PLEX Proinflammatory Panel 1 Mouse Kit: IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, KC/GRO, TNF-α
• V-PLEX Cytokine Panel 1 Mouse Kit: IL-9, IL-15, IL-17A/F, IL-27p28/IL-30, IL-33, IP-10, MCP-1, MIP-1α, MIP-2
• V-PLEX Th17 Panel 1 Mouse: IL-16, IL-17A, IL-17C, IL-17E/IL-25, IL-17F, IL-21, IL-22, IL-23, IL-31, MIP-3α
• V-PLEX Mouse Cytokine 19-Plex Kit: IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12p70, IL-15, IL-17A/F, IL-27p28/IL-30, IL-33, IP-10, KC/GRO, MCP-1, MIP-1α, MIP-2, TNF-α
• V-PLEX Mouse Cytokine 29-Plex Kit: IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12p70, IL-15, IL-16, IL-17A, IL-17A/F, IL-17C, IL-17E/IL-25, IL-17F, IL-21, IL-22, IL-23, IL-27p28/IL-30, IL-31, IL-33, IP-10, KC/GRO, MCP-1, MIP-1α, MIP-2, MIP-3α, TNF-α