Meso Scale Discovery (MSD) Electrochemiluminescence (ECL) Assay for Broad Range Multiplex Detection
Meso Scale Discovery Assay is a bioanalysis platform that utilizes electrochemiluminescence, unlike the colorimetric or chemiluminescent reaction in ELISA, as a signal detection technique. MSD ECL Assays are superior to traditional ELISA in many aspects, even as the various viable assay versions are quite like different types of ELISA. MSD Quick Plex 120 instrument applies the robust and sensitive electrochemiluminescence technology to quantitate single and multiple target analyte. MSD Assays enable accurate determination of analytes in complex biological matrices with improved throughput in a cost-effective and timely manner. Specifically, we can use MSD to analyze many clinically proven biomarkers, perform PK/TK analysis, and carry out ADA immunogenicity testing in a broad range of sample types such as blood, serum, and tissue, etc.
MSD ECL allows simultaneous multiplexing of up to 10 different analytes within the same well. Thus, the MSD platform requires 50-fold less sample than an ELISA method. Below, please see other crucial benefits of the Meso Scale Discovery technology –
- Absolute quantitation, short processing time, and low sample requirement (~10µl)
- High standardization from simple protocols resulting in superior inter-laboratory reproducibility
- Less time/labor intensive for scalability to larger lots
- Low sample volume from human, rodent (mice, rat) and non-rodent (NHP, dog) species
- Higher sensitivity, better dynamic range, and reduced signal-to-noise ratio
- Low analyte levels in small sample volumes
- High/low abundance analytes (normal vs. elevated) within the same sample given large dynamic range
- Limited matrix effect in serum, plasma, tissue culture media (TCM), and various other complex biological matrices
- Ready-made single analyte and multiplex kits with excellent performance and lot-to-lot consistency
- Fit-for-purpose MSD portfolio: 400+ MSD V-plex (pre-validated), U-plex (personalized multiplex), R-plex (not multiplexed), and S-plex (ultra-sensitive) assay
- Most suitable to detect low-affinity anti-drug-antibodies (ADA)
- Emission at ~620 nm solves any color quenching problems
MSD Assay: Electrode Plate Binding with Electrochemiluminescence Quantitation
MSD Assays utilize a carbon electrode plate surface for reagent binding and rely on electrochemiluminescence for ultra-sensitive antigen quantitation. These electrodes in the bottom of multi-array and multi-spot MSD plates can bind up to ten reagents simultaneously. Typically, these reagents bounded to the electrode plate are antigens or antibodies of interest. Below, please see the three most common MSD Assay –
Direct MSD Assay
In Direct Assay, the antigens link the plate and detection antibodies themselves. These direct binding immunoassays are useful when only one antibody is available.
Indirect MSD Assay
In Indirect Assay, these antigens connect the plate with the primary antibody that, in turn, attaches with the secondary detection antibody.
Sandwich MSD Assay
In sandwich assay, both the capture and detection antibodies bind to the antigen to form an antibody-antigen-antibody sandwich. Here, the capture antibody attaches itself to the bottom of the electrode plate. These sandwich immunoassays are useful for high specificity and assay sensitivity when a suitable antibody pair is readily available.
In the MSD-ECL platform, we use detection antibodies linked to SULFO-TAG labels that emit light on electric stimulation in a catalyst buffer. That said, only the tags near the electrified electrodes at the bottom of MSD microplates are excited by the detection process. The MSD instrument applies the electricity to trigger the oxidation-reduction reaction between SULFO-TAG labels and buffer to produce light that gets detected by the MSD CCD camera. Afterward, the Light intensity is measured precisely to quantify analyte levels. The Meso Scale platform operates on high concentrations of Tripropylamine as a catalyst for the reaction with Ruthenium to emit light with 620 nm wavelength.