Cytokines are small secretory proteins that bind to receptors of effector cells and transduce signals among them. Cytokines include interferons, interleukins, growth factors, tumor necrosis factor, and chemokines. Cytokines play a crucial role in immune responses such as inflammation, infection, tissue repair, tumorigenesis, and cellular growth. Hence, it is evident that dysregulation in cytokine response is associated with diseases. Thus, it is essential to understand cytokine responses to investigate disease mechanisms and identify novel therapeutics.
Due to the importance of cytokine functions, profiling multiple cytokines have become crucial for drug discovery and development. A sensitive and robust profiling platform can help identify potential biomarkers and drug candidates. Besides, multiplex cytokine analysis can be a deciding factor in successful drug development programs. Most cytokine profiling technologies are antibody-based immunoassays. Meso Scale Discovery (MSD) is one such promising multiplex cytokine assay. Thus, the current article highlights cytokine profiling with MSD protocol.
How does the MSD test profile multiple cytokines in biological samples?
MSD scale assays are similar to ELISA assays. However, they employ electrochemiluminescence detection technology. Moreover, similar to ELISA formats, MSD has several assay formats. The sandwich format is one of the most employed MSD assays. One key difference between ELISA and MSD is that MSD assays have high-binding carbon electrodes. Also, MSD detection antibodies are linked to a Sulfo-Tag complex, compared to an enzyme in ELISA assays. Once the detection molecule binds to the captured analyte, the supplied current leads to an oxidation-reduction reaction of the Sulfo-Tag molecule, and the CCD camera captures the light signal..
Furthermore, MSD has a multiarray feature in all their assay plates. Multiarray plates have multiple spots within each well. MSD assays have up to four spots for 384-well plates and ten spots for 96-well plates. Researchers can coat each of these spots individually with unique antibodies providing independent results for each spot.
Although MSD and ELISA have similar assay protocols, MSD assays have several advantages. MSD protocol is highly-sensitive and provides a broader dynamic range. The chemiluminescent reaction offers exceptional sensitivity, while the washing step reduces nonspecific binding. Besides, the high-binding carbon electrodes increase the dynamic range of MSD assays. With superior sensitivity, multiplexing capacities, and a broader dynamic range, MSD assays are widely used for profiling multiple cytokines.
Following are some of the features of MSD assays in cytokine analysis.
- MSD assays have numerous singleplex and multiplex assays
- They are highly sensitive and detect within the limits of ~1-10 pg/mL using tissue culture kits
- Ultra-sensitive MSD kits are usually recommended for cell culture applications and complex biological matrices
- A broader dynamic range ensures cytokine measurements at lower and higher levels without dilution
- Spiked samples are easily recovered
- Validation studies performed across several days demonstrate robust assays results
- Most of the assay diluents and protocols are optimized for a wide range of biological samples, including serum, plasma, and cell culture supernatants
- MSD assays are simple and rapid and save time and resources.
Also Read: 6 Tips On Optimizing ELISA Development
Most importantly, MSD assays have comparable results across different technologies and therefore are advantageous in comparative studies.