Does the use of mouthwash before collecting saliva specimen increase the possibility of a false-negative result in COVID-19 testing?

A complex bio-fluid, saliva is secreted by major and minor salivary glands in the oral cavity. It is composed of protein and peptides, hormones, antibodies, and other molecular components, which are helpful for the examination of the physiological and pathological conditions of the human body. Saliva is currently used for the detection of different types of cancer, including oral, breast, and lung cancer, periodontal diseases, diabetes, and acute respiratory syndrome. It is, indeed, considered as a diagnostic window for various pathological diseases [1,2].