Importance

Loading Importance Indicators...

Abstract

A solid-phase binding assay that measures interferometrically either antibodies or binding pair antigens bound to a spinning disc on which the complementary antigen or antibody has previously been coated in an alternating pattern of immunologically active and inactive spots. The spinning disc is inserted into one arm of a Mach-Zehnder interferometer and as the disc spins the bound and unbound spots pass one after another through the two light beams causing a periodic phase shift in the light. These phase modulated light beams are then recombined at a beam-splitter converting the phase modulation into an amplitude modulation. The two recombined beams then fall on a photodetector which converts the periodically varying optical power into a periodically varying electrical current whose amplitude is proportional to the amount of bound protein on the surface of the disc and whose modulation frequency is equal to the frequency with which the spots pass through the light beam. If the disc is spinning rapidly and there are many spots around the disc this signal frequency will be much higher than the frequency of the noise due to the disc wobble and the vibrations imparted to the interferometer by the spinning motor.

Loading the Abstract Image...

First Claim