Enzyme-linked immunosorbent assays (ELISAs) are considered the gold standard for the detection of various immunological reactions and can be used for the detection of infectious diseases during outbreaks or in the care of individual patients. To be useful in the timely implementation of prevention and control measures against infectious diseases, a diagnostic modality should be rapid, accurate, and affordable. In the current study, we demonstrate the efficiency (90% less time and volume consumption compared with those of a standard 96-well ELISA), detection capability, and ease of operation of a field-portable, battery-operated ELISA system, approximately the size of a cellular phone (12 × 6 × 5.5 cm), in the serological diagnosis of measles and rubella viruses that has the potential for onsite testing such as during disease outbreaks.