With multiplex SPR, a large surface area (~1 cm²) of the SPR sensor can be imaged using a camera. Using array spotting technology, an array of multiple protein spots can be deposited within the defined area. Hundreds of spots can potentially be created in this manner. Software allows a user to place regions of interest on the array spots, allowing local tracking of the SPR dips on these spots (see our previous article for more on SPR). In this manner, binding events on all the array spots can be measured simultaneously and in real-time. When deployed as a (antibody) screening tool, the throughput that multiplex SPR offers is orders of magnitude greater than traditional 3-4 channel SPR.

In the figure above, an array of protein spots (48 in this example) is deposited within a defined area of an SPR sensor. Analyte is injected over the entire array and binding events on all spots can be measured simultaneously.