Changeable machine readable assaying indicia

Abstract: A machine readable assaying system comprising a test card having machine readable assaying means. A plurality of individual analysis strips, each strip comprising antibodies and/or reagents capable of indicating the positive presence of distinct illicit substances form a pattern of elements including one or more fixed strips and one or more blank regions. The detection of the presence of a particular substance or drug will result in one or more of the analysis strips changing from a first (light reflective) color to a second darker (light absorbent) color. The pattern of analysis strips, fixed strips and blank regions may be provided to encode one or more characters/digits of information. By the inclusion of the analysis strips with the plurality of fixed strips and blank regions, the detection of one or more illicit substances may alter the overall pattern of fixed and test strips and blank regions, and hence cause the encoded information represented thereby to be altered. Accordingly, the particular pattern of bars and spaces that result from an exposure the physiological fluids of a donor is contemplated to produce a distinct machine readable indicia. The transformation which occurs on the test card will be uninterpretable by the administrator of the test, thus preserving the anonymity and privacy of the tested individual. (end of abstract)