CDC Sample Collection and Testing Guidelines for COVID-19 • Nasopharyngeal (NP) swab is priority for initial COVID-19 testing. Oropharyngeal (OP) swab can also be collected but it is not a priority. If collected, it should e combined in the same tube of NP. Put the swabs directly and immediately into sterile tubes that contain 2-3 ml of viral transport media. Do not use calcium alginate swabs and swabs with wooden shafts as they contain substances which inhibit PCR testing by inactivating some viruses. • Sputum collection is recommended in patients with productive cough. Instruct the patient to rinse their mouth with water and expectorate deep cough sputum into a leak-proof, sterile and screw-cap sputum collection cup or dry and sterile container. • Lower respiratory tract aspirate or bronchoalveolar lavage sample is collected in patients undergoing invasive mechanical ventilation. Collect 2-3 ml in a leak-proof, sterile and screw-cap sputum collection cup or dry and sterile container. • It is necessary to maintain proper infection control during specimen collection.