Bio-plex from Bio-Rad technologies is a leading system of multiplex immunoassays available today. As immunoassays, these allow highly specific and sensitive detection of analytes. The Bioplex assay is a bead-based assay that allows the detection of multiple analytes in a single well or reaction. Given its ability to multiplex, or track several analytes, Bio-plex can be seen as a better option than ELISA assays.
What is a Bio-Plex Assay?
The Bio-Plex multiplex immunoassay system uses the same technology as Luminex assays. Bio-Rad uses a licensed xMAP technology from Luminex to build/manufacture these assays. In a way, these Luminex Bioplex assays utilize the same principle as used by ELISA assays. However, these systems apply the principle to individual beads that are uniquely identifiable.
These beads are constructed to allow multiplexing, thus enabling these systems to detect multiple analytes. Multiplexed immunoassays allow the generation of a wealth of data related to proteins and biomolecules. Thus, these become very useful for clinical use as well as for bioanalysis during drug development.
A big advantage of this method is that a small sample volume can provide a lot of information. Since multiple analytes can be tested per reaction, it also allows time savings. The system allows the detection and quantitation of multiple proteins per reaction.
Since proteins form the key to Bioplex assay, sample measurements differ when measuring plasma and serum. This is because the protein concentration of serum is lower than that of plasma. Generally speaking, plasma has roughly 3-4% more protein than serum. Given the difference, it is critical to choose the right sample matrix to get accurate readings for bioanalysis.
How do these Luminex Bioplex Assays Work?
Luminex xMap technology employs 100 bead sets of different colors. This coloration is done by using two fluorescent dyes in distinct ratios. Each of the beads also gets a unique spectral address matching the color of the beads. A reagent can be added as necessary to further conjugate the beads. The choice of this reagent is specific to the particular bioassay in use.
Antibodies present in the analyte attach to beads of the same color, while a second antibody attaches to the fluorescent reporter dye label. This way, the Bio-Plex microplate format can analyze up to 500 analytes in a single sample. These include nucleic acids, proteins, or peptides. Using different colored beads allows the measurement of several analytes simultaneously.
Once ready, lasers come into action and read the color of each bead and the analyte bound to it. This is used to generate quantitative data from the sample. Often, a dual detection flow cytometer is used to sort out bead colors per channel. One channel measures the analyte concentration, while the other keeps its eyes on the dye fluorescence on the fluorophores.
To aid specific needs related to bioanalysis, assays are available for several cases. It is also possible to customize the Bioplex assay to your specific requirements. These assays are very useful for bioanalytical studies that employ cell-based assays and biomarkers. The bead-based immunoassays and kits are available for several diseases and health issues including inflammation, cardiac disease, autoimmune disorders, diabetes, cancer, and others.