Figure 1.

The point-of-care microfluidics-based combination antigen/antibody assay cartridge and analyzer. Illustration of assay cartridge (A) with sample input port (i), syringe pump adapter port (ii), sample loop (iii), glass fiber pad slot for detection reagent (iv), bubble trap (v), waste reservoir chamber (vi), and 4 × 5 bead array chamber (vii) shows an array of 20 programmable agarose bead sensors (B), with control and antibody capture beads imaged at steps 6 of the assay. The bead sensor serves as a high surface area substrate for developing programmable immunoassays for COVID-19 antibody detection and houses the immunocomplex (C.i). Image analysis for each individual bead sensor is performed by measuring 95% region of interest (ROI) on the bead (C.ii), capturing the many optimally stained and washed immune complexes formed over the bead. The integrated assay is completed in an automated fashion housed in the analyzer with optics, camera, actuator, blister actuators, integrated computer and display, and software to support automated analysis (D). While initial development work was completed with the aid of a commercial microscope, the final implementation was completed using the integrated instrumentation shown here.