A reagent test paddle includes a contamination detection medium, a reference color bar, at least one chemical test medium, and a unique identifier. The contamination detection medium includes a reagent that changes color in the presence or when exposed to a hostile or inhospitable environment. Each chemical test medium includes a regent that is responsive to a respective analyte in a biological sample. The reference color bar includes reference color samples of different colors. The unique identifier, like a serial number, identifies the particular paddle and its chemical test medium so it can be uniquely and anonymously associated with a user. A method includes capturing and interpreting digital images of a biologically unexposed and subsequently exposed reagent test paddle at various delay times within an automatically calibrated environment; locating the paddle in a plurality of digital images, extracting the reference color bar and locating the contamination detection medium and chemical test medium in each digital image. Color changes of the chemical test medium and contamination medium are detected at various delay times after sample exposure. To determine validity of test results, the method further compares the detected colors of the contamination detection medium with predetermined colors expected for no contamination and contamination.

An apparatus includes a mobile computing device (902) physically coupled to a lightbox (904). The apparatus includes camera hardware configured to capture image data associated with an output signal area of a biological chromatographic test strip (410) inserted into a receiving slot of the lightbox. The apparatus further includes processing circuitry in communication with the camera hardware, the processing circuitry being configured to determine, based on the image data captured by the camera hardware, a concentration of a target analyte in a test sample submitted via the biological chromatographic test strip. The apparatus further includes an interface in communication with the processing circuitry, the interface being configured to output data indicative of the concentration of the target analyte determined by the processing circuitry.