Traditional methods of analytical chemistry to detect an interaction between certain proteins in multicomponent mixtures (e.g. cell lysates, etc.) have limitations. This is due to difficulties in identification of a specific signal of an analyte (a molecule to be detected) against the background. In the present work, we propose the new analytical protocol for transducer-based sensors with a restricted sensitive area. It uses a combination of analyte-receptor complex precipitation with serial additions of the receptor (CARSAR). To test this new analytical strategy, we used a surface plasmon resonance technique to confirm an interaction between the Epstein-Barr virus-encoded nuclear antigen 6 and the mitochondrial ribosomal protein MRPS18-2.