LONDON – An attempt to develop an alternative sampling method to replace unpleasant nasopharyngeal swabbing in COVID-19 diagnosis has failed, with researchers at Owlstone Medical Ltd. finding the number of viral particles that can be collected from the breath of hospitalized patients is below the limit of detection. Owlstone is a specialist in collecting and analyzing breath samples to look for volatile organic compounds that are biomarkers of disease, such as lung cancer and asthma.