When Dr. Soo Khim Chan runs what appears to be a regular virus sample through a COVID-19 test, she knows that if all goes well, it will come back positive. But Chan’s sample isn’t from a COVID-19 patient, and it doesn’t even contain the virus which causes the disease. Instead, she’s using a virus-like nanoparticle called a probe — essentially a fake coronavirus. Although they’re only being used for research purposes at this stage, and were only made in the lab, these probes…