"Several other tests are based on a technique called loop-mediated isothermal amplification (LAMP), which also works at a constant temperature and has been used to identify viruses such as Zika. LAMP relies on two enzymes — one to convert the viral RNA to DNA, and another to copy DNA — as well as a set of four to six short primers designed to recognize different snippets of the viral genome. These fragments not only help to get the copying started, as in RT-PCR, but also allow newly copied DNA strands to form looped structures that can be amplified much more rapidly than in standard PCR (see ‘Loop the loop’). It is less accurate, however, and only a few dozen samples can be run at a time. Because the technique doesn’t need special instruments, it can be used in the field and in regions that lack advanced equipment, including remote areas and refugee camps, says Vicent Pelechano, a genomics expert at the Karolinska Institute in Stockholm, who co-developed a LAMP-based assay for SARS-CoV-2. “All you need is a test tube containing the primers, a pipette, a hotplate and a pot of water,” he says. A single test would cost about $1 — not counting labour. In the lab, Pelechano and colleagues’ LAMP-based test could detect as few as 10 copies of a SARS-CoV-2 genome in no longer than 40 minutes1. The researchers then tested the assay using samples from 248 people with confirmed coronavirus infection, and could detect the virus nearly 90% of the time2. Pelechano acknowledges that the test might turn out to be less accurate for some samples, such as those contaminated with blood. But in some places, the trade-off in accuracy could be worth it. Low-income countries and war-torn areas don’t have enough PCR machines to perform the standard diagnostic test for coronavirus, says Nabil Karah, a clinical microbiologist at Umeå University in Sweden. Karah is working with other scientists and with Pelechano’s team to bring their LAMP-based test to Syria to increase local testing capacity."