Thursday, July 8, 2010
More sensitive biomarker detection in blood requires single protein molecule screening for diagnostic purposes. Microscopic beads with specific antibodies provide flexibility to detect low-abundance proteins in blood. Conventional ELISA can work with an ensemble of proteins linked with antibodies, however, analyzing single proteins is needed for low concentration targets in blood. Towards this end, Quanterix Corporation introduced a technology that can isolate single beads with 50-fl reaction chambers, which also are monitored by fluorescent imaging. They demonstrated the detection of as few as ~10–20 enzyme-labeled complexes in 100 μl of sample (~10−19 M) and routinely allowed detection of clinically relevant proteins in serum at concentrations (<10−15 M) much lower than conventional ELISA
Please check out the recent report in Nature Biotechnology on Single-molecule ELISA.