Abstract: A machine readable assaying system including a test card providing a machine readable assaying arrangement. At least one analysis strip is provided, possibly including antibodies and or reagents capable of detecting and optically indicating the presence or absence of at least one substance present within a volume of physiological fluid. The analysis strips composing, at least in part, an assaying mechanism in the form a pattern of elements, generally additionally including at least one fixed strip, and at least one blank region. Each analysis strip, upon contacting the physiological fluid of a donor for a suitable temporal interval, may effect a change from a first state having a first reflectance level to a second state having a second substantially different reflectance level, thereby altering the pattern formed by the assaying mechanism. The particular pattern that results from an exposure to the volume of the physiological fluid is contemplated to produce a distinct machine readable indicia.