Magnetic nanoparticles are an increasingly common feature in diagnostics. With their ability to disperse evenly throughout a medium, the reactive surface area of functionalized nanoparticles exhibit superior kinetics in capturing target analytes with high efficiency. NVIGEN’s nanoparticle-based ELISA assays are thus rapid, highly sensitive tests with shorter incubation times that enable a smoother workflow, provide superior results, and support multiplex assays.
Figure 1. Overview of On-Beads ELISA Assay.
- KE7101 MagVigen™ – PD-L1 On-Bead ELISA Kit
- KE7102 MagVigen™ – Her-2 On-Bead ELISA Kit
- KE7103 MagVigen™ – EGFR On-Bead ELISA Kit
On-Beads-ELISA Assay General Protocol:
Figure 2. Basic Workflow for On-Bead ELISA Assay.
- Antigen capture: Mix sample with antibody-conjugated beads, which will rapidly capture analyte such as sPD-L1.
- Wash: Place plate on an NVIGEN magnetic plate (cat#A20008) and wash plasma and other proteins from the plate. The NVIGEN magnetic plate is designed to magnetize the beads into a pellet so that the supernatant can be easily removed.
- Incubate with enzyme-bound detection antibody: Mix detection antibody in assay diluent and incubate with the beads.
- Wash: Wash excess enzyme from the plate, again using the NVIGEN magnetic plate to pellet the beads between wash steps.
- Add Detection Solution: Add detection solution, pipet up and down to mix, incubate for 15 minutes for the reaction to proceed.
- Transfer detection solution to new plate, read on plate reader: Transfer the supernatant to a clean plate and read the results using a standard plate reader.
Our bead-based PDL1 assay notably exhibits over 6x the sensitivity of a standard ELISA in which capture antibodies are adsorbed onto a plate surface. Additionally, due to the optimal bead kinetics, our assay can be performed in a fraction of the time compared to competing assays, with a lower limit of detection at 0.1 ng/mL.
Figure 3. On-Bead Elisa PD-L1 Assay Performance.
Comparison of standard on-plate versus on-bead ELISAs done in human plasma. On-Bead ELISAs demonstrate superior linearity, signal, and sensitivity. Low-end detection threshold is approximately 100 pg/mL with 200 uL of human plasma sample.