To defend the body, the immune system makes proteins known as antibodies that latch onto the perceived threat, be it HIV, the new coronavirus or, as is the case in autoimmune disease, part of the body itself. In a new proof-of-concept study in ACS Sensors, researchers describe a new system for detecting antibodies within a pinprick of blood within minutes, using an unlikely combination of cotton thread, glowing proteins and a smartphone camera.
While some tests simply detect the presence of an antibody, sometimes doctors want to know how much is circulating in the blood. Such quantitative tests are used to diagnose a number of conditions, including infections and autoimmune diseases. Although a quantitative antibody test is not yet approved for use in the U.S., such a test could potentially aid in assessing immunity to SARS-CoV-2. However, quantitative testing currently requires expensive, sophisticated instruments in labs, and efforts to make it more accessible have had only limited success. So, Maarten Merkx, Daniel Citterio and colleagues tested an approach that could provide a small, inexpensive alternative.
