DiscussionLabel-enhanced SPR is a new concept which greatly improves the sensitivity and specificity of SPR analyses. Label-enhanced SPR can be used directly on standard SPR instruments and does not require any modification of the existing SPR instrument hardware.
Here we show that the increased sensitivity from the label-enhanced SPR concept enables binding kinetics analysis of fragments and low-molecular weight (LMW) compounds in Biacore 2000, using carbonic anhydrase II and various inhibitors. The data are cleaner because the noise, drift and bulk effects are reduced. The signal-to-noise ratio improvement, calculated as the measured binding signal at saturation divided by the baseline noise level, is about 100x.
Label-enhanced SPR offers the following benefits as compared to conventional label-free SPR:
• 100x increased sensitivity, markedly improving the confidence level of the results.
• Accurate kinetic analysis of small-molecule binding in the competitive format.
• An increased robustness towards noise, drift, spikes, and bulk effects, simplifying and speeding up the assay development process.
• Reference subtraction not needed, leading to reduced chip consumption and higher sample throughput.