Researchers from the California NanoSystems Institute at the University of California, Los Angeles (UCLA; CA, USA) have developed a device based on a mobile phone that can read ELISA plates. The study, recently published online in ACS Nano, reported that the new technology can perform with the same degree of accuracy as the much larger machines typically found in clinical laboratories.
Currently, 96-well plates are used for ELISA testing; samples are distributed to the wells, and then specific antibodies are added that can bind to antigens that may be present in the sample. As the antibodies are linked to enzymes, binding to an antigen causes an enzymatic reaction to occur. This produces a change in the color of the well contents, and this color change can then be measured to detect and quantify the antigens present in the sample.
The UCLA team used a 3D printer to create the new device, which includes an array of light-emitting diodes. These illuminate the ELISA plate – the light passes through each well and is detected by 96 individual plastic optical fibers in the attachment. A custom-design application on the smartphone then transfers the resulting images to UCLA servers and a machine-learning algorithm, written by the research team, then analyzes these images. Within about 1 minute the results for the whole plate are the fed back to the phone.
To test the accuracy of the new device, researchers compared it to the existing well-plate readers in a UCLA clinical microbiology laboratory, which are standard FDA-approved machines. The study suggests that the mobile-based device can detect antigens with the same level of accuracy as the conventional plate readers, and incorporated tests for herpes simples viruses 1 and 2, mumps and measles.
The leader of the research Aydogan Ozcan, associate director of the California NanoSystems Institute, commented on the potential applications of the new device: “This mobile platform can be used for point-of-care testing, screening populations for particular diseases, or tracking vaccination campaigns in most resource-poor settings.”
The research team is now seeking to adapt the design of the mobile-based reader to create similar quantified readers for other medical tests.
Sources: Berg B, Cortazar B, Tseng D et al. Cellphone-based hand-held microplate reader for point-of-care testing of enzyme-linked immunosorbent assays. ACS Nano DOI:10.1021/acsnano.5b03203 (2015) (Epub ahead of print); UCLA researchers create smartphone-based device that reads medical diagnostic tests quickly and accurately.