Creative Biolabs is one of the well-recognized experts who are professionals in microfluidic development for heterogeneous immunoassay. Our scientists are proud to tailor the best-fit microfluidic strategies to meet your specific project requirements with over ten years' extensive experience and our advanced microfluidic platforms.
In heterogeneous immunoassays, antibodies are immobilized on a solid support and interact with the antigen at the boundary layer. In this format, unbound antibodies and other reagents can be easily removed. All heterogeneous immunoassay configurations are composed of three components: the capture system, the analyte (i.e., the substance that the assay is designed to measure, either antibody or antigen) and the detection system.
To improve the throughput of these processes, heterogeneous immunoassays can be easily implemented in microfluidic platforms and benefit from the high ratio of surface area to the volume that gives higher sensitivity. Immobilization is the most important step in heterogeneous immunoassays because it dramatically influences specificity and sensitivity. Briefly, the surface of microfluidic chips has to be treated so that proteins can be immobilized for further detection. In general, solid phases can be grouped into two categories, surface-based and bead-based methods.
Many surface-based immobilization strategies and different substrate materials such as PDMS, cycloolefin-copolymer, PS, silicon nitride (SN), and PMMA can be used for heterogeneous immunoassays.
Bead-based immobilization can be classified as nonmagnetic microbeads (PS beads and glass beads) or magnetic microbeads in microfluidic immunoassays. Microbead-based immobilization could offer a large surface area and may improve the performance of the immunoassays.
Among the several immunoassay formats developed to meet specific clinical needs, heterogeneous immunoassay is one of the most essential types due to its higher sensitivity. The current application of these formats allows the analysis of clinically important disease biomarkers acting as antigens like C-reactive protein (CRP), prostate-specific antigen (PSA), ferritin, vascular endothelial growth factor (VEGF), and others. Immunoassay of larger biomaterials like viruses, bacteria, and allergens can also be applied to different microfluidic formats.
For example, a microfluidic electro-immunosensing chip for simultaneous determination of cancer biomarkers, including AFP, CEA, and prostate-specific antigen, has been developed. The required components for this entire assay, such as micropumps/microvalves for liquid delivery, microsensors for control, are all integrated on a single chip. In this work, the capture Ab-conjugated beads are introduced and trapped in the reaction area by PDMS micropillars, followed by introducing samples containing cancer markers, gold nanoparticles-labeled detection Ab, and silver enhancer, respectively. Compared with conventional immunoassays, the analysis time is reduced from few hours to an hour.
Fig.1 Schematic illustration of the detection method based on immunogold silver staining. (Lin, 2010)
Creative Biolabs is a world-leading services provider in the field of microfluidic chip development. Equipped with advanced platforms and powerful technologies, we are dedicated to supporting heterogeneous immunoassay by developing a high-quality and high-sensitivity microfluidic chip system. If you are interested in our custom services, please do not hesitate to contact us to discuss your project.
For Research Use Only. Not For Clinical Use.