The Biacore 1S+ is a new surface plasmon resonance (SPR) instrument for label-free binding interaction analysis, similar to the older T200 it replaced in our core at 953 Indiana. It is designed for serial analysis of samples across six flow cells (five active cells and one reference) and therefore offers higher throughput than the T200’s four flow cells. The sensitivity is comparable to the T200 and the UX is designed for simplified training and operation. The 1S+ can measure low concentration analytes (down to 1 pM), very slow off-rates (down to 10-6 s-1), and weak binding of small molecule fragments (up to mM affinities).