Cytokines are proteins or peptides produced by the immune system that are important in regulating the immune response. Cytokines regulate the maturation and responsiveness of the cell population, modulate immune responses, and are crucial mediators in health and disease states. Besides, the cytokine storm delivers insights into the pathophysiological processes and provides early indications of various diseases. Hence, determining cytokine behavior is crucial in understanding the complex signaling pathways in disease or normal states.
Having said that, what is drug development? Drug development is the process of identifying potential drug compounds against disease and medical conditions. In recent years, Luminex assays have been widely used in early-stage drug development to assess cytokine behavior. Although Luminex assays are ideal for analyzing cytokines, ELISA has been traditionally used for evaluating target analytes in biological samples. However, Luminex assays have several advantages over ELISA. Let us understand the differences between ELISA and Luminex cytokine assay.
Differences between Luminex cytokine assay and ELISA
Compared to ELISA kits, Luminex assays are expensive and require specialized equipment. Therefore, understanding the difference between Luminex and ELISA assays is necessary to help researchers decide the best assay type for their individual research needs.
The primary difference between ELISA and Luminex analysis is the use of different target capture and reporter systems. Luminex assays capture analytes on spherical beads, while ELISA uses microplates for capturing the target analytes. Fluorescence is the reporter system in Luminex assays, whereas ELISA employs enzymatic reactions of a colored substrate. Moreover, Luminex has digital signal processing capabilities to classify the dyed beads with different proportions of fluorophores. These distinct regions have a specific spectral signature in each bead population.
Luminex analysis has several advantages over traditional ELISA and microarrays. Each microsphere of a Luminex assay is conceptually an ELISA on a bead. This system means that each bead is equal to an individual ELISA assay. Such functionality enables the analysis of 100 different targets in a single well of Luminex assays. Besides, the 3D structure and smaller surface area empower faster reaction kinetics and reduce the run time compared to ELISA assays.
Besides, custom Luminex assays allow the attachment of specific probes that can rapidly expand and adapt to mutations in the population, making it an ideal screening tool. Furthermore, Luminex requires only 50 μl of sample assay volume per well. This assay volume is relatively low compared to ELISA assays. Hence, more data can be obtained from limited sample volumes. Moreover, analysis of samples such as cerebrospinal fluid that are difficult to obtain or are present at low volumes becomes easy with Luminex assays.
Compared to ELISA assays, Luminex analysis provides both high-throughput and high-density analysis with reliable, reproducible, and accurate results. Although ELISA can provide high-throughput analysis, it can’t multiplex more than a few tests at a given time. On the other hand, microarrays can provide high-density screening but lack the reproducibility required for high-throughput analysis.
However, there are several factors to consider before using Luminex cytokine assays. Luminex assays require dedicated instruments, which may increase the upfront costs of Luminex analysis. Although, the development of light-emitting diode-based systems can help decrease the setup costs. Besides, differences in assay manufacturer, assay execution, and product lot number can cause variability in Luminex results. Additionally, human autoantibodies in biological samples may hinder the measurement of cytokines in biological samples.