When it comes to coronavirus testing, the problem is simple: there are too many people to test, and too few kits to test them with. That’s why researchers across the world are having to improvise. One promising technique is group testing, in which multiple people are testing at once.

Group testing, also known as pool testing, is a technique that’s been around since World War II when the U.S. Army first employed it to suss out syphilitic soldiers. Rather than pay for each soldier to undergo a costly test, officials would combine blood samples from a group of soldiers and then test that joint sample. If the test came back negative, all the men could be assumed free of the disease. If it came back positive, the Army could test the soldiers in that group individually to find the one (or more) with syphilis.

Now, researchers in the United States, Israel, and other nations are employing the technique to the coronavirus outbreak  — and they’re finding the method to be incredibly effective.

On March 24, Peter Iwen, director of Nebraska’s Public Health Lab, began using group coronavirus testing as a way to save valuable time and supplies. He split 60 samples into 12 groups of five before testing and found he was able to effectively identify all of the positive samples in the group using 24 kits instead of the usual 60. That’s far more efficient than the usual case-by-case testing.

During a group coronavirus testing trial in Israel, meanwhile, researchers tested up to 64 samples at once — and if even one sample in the group was positive, the test was able to detect it. Based on these results, implementing group coronavirus testing on a wide scale could allow nations to dramatically increase the number of people they test. Now that’s what we call ingenuity.