Abstract: An immunotherapy treatment for a patient infected with the virus giving rise to the acquired immune deficiency syndrome (AIDS) and resulting in a breakdown in the patient's immune response. In this treatment, a supply of plasma is derived from serum-positive individuals who carry the AIDS virus yet are free of the clinical symptons associated with AIDS or with any AIDS-related complex. The plasma supply is processed to provide a preparation rich in antibodies having neutralizing properties in respect to the AIDS virus, the processed plasma being free of red blood cells and other impurities. The processed plasma is transfused intravenously into the infected patient in a dosage which is safe and efficacious, and the transfusion procedure is repeated at spaced intervals of time until the deficiency in the immune response of the patient is substantially overcome.

Abstract: A method of testing a fluid sample for the presence of antibodies against a micro-organism, which comprises contacting the sample with fixed cells or fragments of cells infected with the micro-organism, and determining the presence of antibody bound to the cell-associated antigens, in which the determination is by virtue of a color change visible to the naked-eye at the site of the antibodies. For use in a testing method of this type, a test component comprises upper and lower layers, in which the upper layer has an array of apertures through which discrete areas on the lower layer are exposed, and in which the lower layer carries, in some at least of the discrete areas, fixed cells or cell fragments infected by a micro-organism.