Coronavirus tests taken at an assisted-living facility in Chevy Chase were processed at a lab that was shut down by the Maryland Department of Health for not having the right certification to do the testing. State health officials had previously disclosed that the Greenbelt lab, Advanced Pain Medicine Institute (APMI), handled samples collected from three pop-up clinics at churches last month. But in a letter to residents and their families this week, the administrator of the assisted-living facility said some of its tests had also gone to APMI. What’s not clear is how the facility’s samples ended up at APMI. In her letter, the administrator described the situation as being the result of a contract between another lab, named CIAN Diagnostics, and APMI. But Sam Mullapudi, a principal at CIAN, denied having any business relationship with the facility and said that he now suspects his two salesmen of sending work to APMI without his knowledge.