Instantaneous cloth-based enzyme immunoassay for the semi-quantitative visual determination of antibodies

An antigen-coated cloth segment was placed onto a blotting pad. The cloth was blotted with one drop of an antibody sample, immediately washed with five drops of a washing solution, exposed to one drop of an anti-antibody-peroxidase conjugate, washed, and finally exposed to a peroxidase substrate. The colored peroxidase product was determined either visually or colorimetrically with the color intensity being correlated to the antibody concentration. This rapid assay would facilitate field serodiagnosis of human and animal diseases.