Conjugation of ACE2 and Control Antibodies to Magnetic Microspheres to Capture Viral Particles from SARS-CoV-2 Infected Cells

To begin, prepare the working solution of NeutrAvidin in MES buffer in a 1.5-milliliter low protein binding microfuge tube. Then prepare the working solution of goat immunoglobulin G control antibody in MES buffer. Vortex the diluted antibody solution, and centrifuge the tube.

Next, take the Microtiter plate containing activated beads and place it on a magnetic plate separator for 30 seconds to immobilize the beads. With the Microtiter plate still positioned on the magnetic separator, aspirate the supernatant from magnet immobilized beads. Then add 100 microliters of NeutrAvidin solution, antibody solution, and MES buffer to appropriate wells containing beads.

Seal the Microtiter plate and incubate for two hours on an orbital shaker at 650 RPM in the dark at room temperature. Then wash beads with PBST using an automated washer. After overnight incubation, prepare the recombinant human biotinylated ACE2 and biotin working solution in 10 millimolar PBS.

Immobilize the microspheres on the magnetic plate separator for 30 seconds, and aspirate the supernatant from magnet immobilized microspheres, as shown earlier. Remove the Microtiter plate from the magnetic separator, and add 50 microliters of 10 millimolar PBS to each well. Then add 100 microliters of the biotinylated ACE2 and biotin working solution to appropriate wells containing NeutrAvidin conjugated microspheres.

Seal the Microtiter plate, and incubate for one hour on an orbital shaker, as shown earlier. After washing the microspheres, store the ACE2 and biotin conjugated microspheres.