He pours the sample into the slot and waits. Soak your arm in warm water and avoid heavy activity. It will improve in two weeks. That evening while thinking how amazing this new technology was, Jack began wondering if the computer could be fooled. He mixed some tap water, a stool sample from his dog, urine samples from his wife and daughter, and masturbated into the mixture for good measure.
Jack hurries back to the drugstore, eager to check the results.
He deposits ten dollars, pours in his concoction, and awaits the results. Your tap water is too hard. Get a water softener. Your dog has ringworm. Bathe him with anti-fungal shampoo.