A simple visual surface immunology test.

A new general immunology test is described which is capable of detecting protein in the 1 microgram/ml range. First an antigen is adsorbed in a small area of a glass surface. The glass is exposed to an antibody solution and the antibody will attach specifically to the antigen. Next the slide is washed, dried and sprayed lightly with plastic particles that stick to the protein layers on the glass. Now when the glass slide is exposed to an acid the antigen--antibody bonds are broken, the antibodies will leave the surface removing some of the plastic particles and leaving an easily visible spot behind.