An analytical test device for competition assay for particular non-protein antigens, such as antigens representing drugs of abuse, is disclosed. The analytical test device is a test kit housing having an opening for introduction of a body fluid sample and a flow path for the body fluid sample. A supply of microscopic colored latex particles is adjacent to the opening along the flow path. A chromatographic membrane support is within the test kit housing for exposing the colored latex particles to the body fluid sample. When non-protein antigens are not present in the body fluid specimen, the colored latex particles accumulate at a predetermined site on the chromatographic membrane by complexing of antibodies on the colored latex particles to a drug conjugate probe on the membrane support to leave a visually perceptible colored mark of the same color as the colored latex particles. When non-protein antigens are present in the body fluid specimen, complexing of the non-protein antigens to the supply of antibodies on the colored latex particles exhausts the antibody supply on the colored latex particles such that the colored latex particles cannot complex to the immobilized drug conjugate probe, leaving no visually perceptible colored mark at the predetermined site. Also disclosed is a process for analytical testing of a body fluid for the presence of non-protein antigens, and an analytical test assembly for simultaneous multiple competition assays.