COMPARISON OF THE QCM AND THE SPR METHOD FOR SURFACE STUDIES AND IMMUNOLOGICAL APPLICATIONS

A comparison between the quartz-crystal microbalance (QCM) and surface plasmon resonance (SPR) using an especially designed flow-through cel l for simultaneous measurements and flow-injection analysis (FIA) is p resented. We compare the effects due to unspecific binding of bovine s erum albumin (BSA) to gold surfaces, specific binding between BSA and monoclonal antibodies, regeneration experiments, serum experiments wit h HIV antigens and the influence of the bulk properties of liquid samp les. The basic theory and its consequences on measurement signals and experimental methods are discussed. The fundamental problem of the com parability of different measurement principles is considered. We sugge st guide parameters, which allow an objective judgement of the perform ance. We do not find any advantage of one particular system concerning sensitivity and cross sensitivity.