Patent ID: 7889347

Claim:
An instrument, comprising: a semicircular rail; a sample stage for receiving a sample, the sample stage forming a plane; a light source mount on the rail; a light source on the light source mount; a detector mount on the rail; a detector on the detector mount; a driving mechanism, wherein the driving mechanism comprises: a) a driving bridge having a first pivot point and a second pivot point; b) a first swing arm with a first end and a second end, the first end being connected to the driving bridge through the first pivot point; c) and a second swing arm with a first end and a second end, the first end being connected to the driving bridge through the second pivot point, wherein the second end of the first swing arm is connected to a pivot point on the light source mount and the second end of the second swing arm is connected to a pivot point on the detector mount; and a controller configured to drive the light source mount and the detector mount to move synchronously along the rail in opposite directions through a range of angles, receive a signal from the detector at a plurality of angles within the range, the signal corresponding to surface plasmon resonance responses, select an angle corresponding to a desired surface plasmon resonance response characteristic, and drive the light source mount and the detector mount to the selected angle.