A point-of-care COVID-19 test can now detect and differentiate the alpha variant of the SARS-CoV-2 virus from earlier strains in saliva samples. The new test builds on the group’s previous developments, which allowed samples to bypass the laboratory — first using nasopharyngeal swabs, then with saliva samples. The point-of-care amplification and testing process, called LAMP, is more efficient than PCR because it does not require expensive thermal cycling machines. The researchers say the assay does not need RNA extraction and purification steps, similar to the Illinois saliva test.
During the new testing process, specially selected genetic primers are placed onto additively manufactured cartridges and dried before adding the patient samples. The chosen primers are set against the S-gene and are specific for detecting the S-gene target failure against 69–70 deletion in the alpha variant, the study reports. The study confirmed the device’s effectiveness by testing 38 clinical saliva samples, including 20 samples positive for alpha variant.
The researchers say they would like to refine their method to test up to five different viruses, viral strains and variants in a single test, compatible with nasal swab and saliva mediums.