The present invention relates to a method for evaluation of an interaction between an analyte in a fluid sample and a ligand immobilized on a sensor surface of a biosensor, comprising the steps of providing (101) a plurality of fluid samples, each containing known concentrations of analyte providing (102) a plurality of needles and a plurality of sensor surfaces or detection spots, at least some of the sensor surfaces or detection spots having a known amount of ligand immobilized thereon, and each needle being configured to inject a fluid sample to a sensor surface or detection spots dividing (103) said plurality of fluid samples into at least two groups injecting (104) the fluid samples of a first of said groups to the sensor surfaces or detection spots by means of the needles to permit association of the analyte to the ligand monitoring (104) each sensor surface or detection spot and collecting binding data, and repeating (105) the steps of injecting fluid samples and monitoring detection spots and collecting binding data for each group of fluid samples, wherein the steps above are performed sequentially, without intermediate regeneration or renewal of the immobilized ligand. The invention also relates to a biosensor system for evaluation of an interaction between an analyte in a fluid sample and a ligand immobilized on a sensor surface, to software for performing the steps of the method and to a computer readable medium for storing said software.