SPR Overview


Surface Plasmon Resonance (SPR) is a powerful technique to measure biomolecular interactions in real-time in a label free environment. While one of the interactants is immobilized to the sensor surface, the other are free in solution and passed over the surface. Association and dissociation are measured in arbitrary units and displayed in a graph called the sensorgram.

Biomolecular Interaction Analysis is not limited to proteins. Interactions between DNA - DNA, DNA - protein, lipid - protein and hybrid systems of biomolecules and non-biological surfaces can be investigated.

Biomolecular Interaction Analysis can be used in a number of ways.

  • To identify the binding of two or more interactants to each other
  • To determine the affinity of the interactions
  • To measure the actual association and dissociation rates

In addition, the binding of two interactants can be exploited to quantify the concentration of one of the interactants.


This website will introduce biomolecular interaction analysis in combination with surface plasmon resonance. Both theory and practice will be discussed. The main emphasis will be on avoiding pitfalls and designing proper experiments. Although written with the Biacore™ instrument in mind, the general principles and guidelines will be applicable to comparable SPR instruments.

Although many SPR instruments are highly automated, it is imperative to know how to design a proper experiment. From choosing the reagents, designing the experimental setup, performing the experiment, analysing the data and publishing the results, each step takes time and effort. Scientific experimenting is often called research, which means that it is an iterative process. Repeating the experiment will lead to more accurate and reliable results. So, keep in mind to optimize the previous step before going on to the next and review every result with care.