Getting tested for an STD is a pain. There's a doctor's appointment, a week of waiting for results and a wealth of opportunity for embarrassing human interaction. These hassles may be part of the reason STD infection rates are on the rise—so now a clinic in London has begun to reimagine the process for the digital age. Its walk-in facility, called Dean Street Express, seeks to provide a self-service, stigma-free experience that requires almost no eye contact with strangers. And the system is working thanks to a miniaturized version of molecular-testing technology.

After scheduling a time online, a person concerned about STDs arrives at the Dean Street clinic and checks in on a computer screen. A technician then hands the subject a tube with the appropriate swabs for tests that were selected from a menu (which includes all the standards such as syphilis, gonorrhea and chlamydia). Next the individual enters a private room where a video shows how to provide samples. Results are texted to a mobile phone within six hours.

The technology that makes this possible was developed by Cepheid, a U.S.-based diagnostics company whose portable tuberculosis test hit the market in 2011, then skyrocketed in popularity for its ability to get from sample to result in just 15 minutes. Just like laboratory tests, Cepheid's method relies on genetic markers to pinpoint disease—but it all takes place inside a machine that is small enough to be carried around. Within five years the company has sold nearly 12,000 testing systems in countries that, in some cases, had never seen molecular testing before. Hoffmann–La Roche, Abbott and other companies have since developed similar systems.

In London, the Dean Street model has been so popular that the company's founders recently introduced HIV testing and opened a second location. Five more are planned for the city, and Cepheid says it is also providing systems for walk-in clinics in Barcelona, Paris, Brisbane, Australia and San Francisco (with one about to launch in Florida). Says Dave Persing, the testing company's chief medical officer: “Everybody sees the potential here to shorten the time to result and get patients on therapy much more quickly, reduce transmission, reduce anxiety and provide an overall better experience. Nobody likes getting surprised 11 days later that they're positive for chlamydia or gonorrhea. That's just unacceptable.”