From dip to sensorgram
A sensorgram or biomolecular interaction plot is a graph of the angle (Y-axis) at which the dip (see technology) is observed vs. time. First, no change occurs at the sensor and a baseline is measured with the dip at a certain starting SPR angle. After injection of the sample (arrow) biomolecules will adsorb on the surface resulting in a change in refraction index and a shift of the SPR angle occurs. In the IBIS MX96 all the Regions of Interest can be followed simultaneously (> 500) resulting in a large number of sensorgrams from a single injection.
Rotated presentation of the SPR-dip (left section) that forms directly the pointer of the sensorgram (right section). The shifts are linear with the accumulated mass over a broad range. The SPR-dip of the initial curve (A) shifts with time towards a higher angle (B). In the sensorgram on the right, the angle shift as a function of time is shown after injection (arrow) of the sample. (See Handbook of SPR)