An automated point-of-care system for immunodetection of staphylococcal enterotoxin B

An automated point-of-care (POC) immunodetection system for immunological detection of staphylococcal enterotoxin B (SEB) was designed, fabricated, and tested. The system combines several elements: (i) enzyme-linked immunosorbent assay-lab-on-a-chip (ELISA-LOC) with fluidics, (ii) a charge-coupled device (CCD) camera detector, (iii) pumps and valves for fluid delivery to the ELISA-LOC, (iv) a computer interface board, and (v) a computer for controlling the fluidics, logging, and data analysis of the CCD data. The ELISA-LOC integrates a simple microfluidic system into a miniature 96-well sample plate, allowing the user to carry out immunological assays without a laboratory. The analyte is measured in a sandwich ELISA assay format combined with a sensitive electrochemiluminescence (ECL) detection method. Using the POC system, SEB, a major foodborne toxin, was detected at concentrations as low as 0.1 ng/ml. This is similar to the reported sensitivity of conventional ELISA. The open platform with simple modular fluid delivery automation design described here is interchangeable between detection systems, and because of its versatility it can also be used to automate many other LOC systems, simplifying LOC development. This new POC system is useful for carrying out various immunological and other complex medical assays without a laboratory and can easily be adapted for high-throughput biological screening in remote and resource-poor areas.