Cambridge (MA) startup Quanterix is developing a protein-detection technology that can count single molecules in blood samples.
The technology uses microwells etched into an optical fiber and coated with protein-capturing antibodies. Each well is 2.5 µm wide and sits at the tip of an individual thread of the fiber. If the antibodies capture a protein from a blood sample, a chemical reaction will be triggered and fluoresce when light is sent up the fiber. The concentration of a protein in a blood sample is indicated by the number of microwells lighting up.