healthcare professional holding coronavirus covid-19 test kit equipment

covid coronavirus pcr swab test kit equipment doctor sample analysis collection antigen care check clinic research contamination convalescent corona coveralls diagnostic disease elisa epidemic hazmat health hospital lab laboratory medical nasal nasopharyngeal negative pandemic patient polymerase chain reaction positive ppe protective reinfection saliva specimen staff suit symptoms throat viral virus healthcare professional holding covid-19 equipment patient examination analysis lab scientist personal inspecting sterile dna tube