Possibly now more than ever, devices and methods that make antibody detection widely available and user-friendly are extremely sought after. Such tests could help to diagnose conditions and even assess disease immunity. An innovative and unusual antibody assay has been proffered as a user-friendly solution to laboratory-dependent and time-consuming analytical techniques.
This assay comes in a rather unexpected form – a glowing thread. A cotton thread provides a platform for a series of fluorescent proteins, which undergo a conformational change when bound by specific antibodies. This binding causes a change in the colour of the fluorescent light emitted by the proteins. The researchers of this proof-of-concept study claim effective detection of anti-HIV, influenza and dengue virus antibodies, as well as quantitative measurements of antibody concentration. Qualitative results provide invaluable insight into disease exposure, but quantitative insights could potentially help assess an individual’s immunity to certain diseases.
In addition, the results can be detected using a smartphone, via the use of a 3D-printed case and lens adapter. The smartphone could also be used for the necessary computation, further removing the necessity for specialised intervention. Though the custom adapter does not make this approach immediately practicable for an average consumer, steps have certainly been taken towards providing broadly accessible detection methods.
While this study did not incorporate antibodies specific to the novel coronavirus, SARS-CoV-2, the current health crisis certainly highlights the potential applications of this technology.
The researchers’ microfluidic thread-based analytical device (μTAD) relies on light-emitting sensor proteins held on a thread. In the presence of the right antibodies, the color of the light emitted by the sensors changes. The shift, from green to blue, correlates with the concentration of antibodies in a sample.