A MICROSCALE METHOD EMPLOYING SURFACE-PLASMON RESONANCE DETECTION FOR THE DETERMINATION OF CONDITIONS FOR IMMUNOAFFINITY CHROMATOGRAPHY OF PROTEINS

The BIAcore(TM) Biosensor System utilizes a detection principle known as Surface Plasmon Resonance (SPR) which, in simple terms, detects changes in the refractive index of a solution in contact with a gold film. The gold film is surface modified with carboxymethylated dextran to produce a hydrophillic matrix onto which macromolecules may be covalently immobilized. In this respect, the BIAcore(TM) is similar to any other insoluble matrix, such as a chromatographic support. The SPR detection principle, however, allows one to directly 'visualize' the interaction under study, in real time and without the need for reporter molecules such as enzyme-labels. In addition, the very small sample requirements, automated robotics unit and ease of data analysis suggest the potential use of the BIAcore(TM) instrumentation for assay development and possibly process development, especially where bio-specific interactions such as immunoaffinity chromatography are used as a step in the process. In this report, we demonstrate the use of the BIAcore(TM) SPR detector for the micro-scale determination of conditions for immunoaffinity chromatography of soluble complement-receptor 1, sCR1.