The highly conserved, cardiotonic steroid binding site (also termed ouabain binding site) on the primary α subunit of Na,K-ATPase plays a receptor signaling role in a range of vital cell processes and is a therapeutic target for human disease. Mouse lines with altered affinity for cardiotonic steroids on the α1 or α2 subunit isoform of Na,K-ATPase, without any change in pump activity, were developed by the late Jerry B Lingrel and are a valuable tool for studying its physiological roles and drug actions. In one model, the normally ouabain resistant α1 isoform was rendered sensitive to ouabain binding. In a second model, the normally sensitive α2 isoform was rendered resistant to ouabain binding. Additional useful models are obtained by mating these mice. To further advance their use, we developed a rapid, real-time PCR method that detects mutant alleles using specific primers and fluorescent probes. PCR is performed in fast mode with up to 15 samples processed in 40 min. The method was validated by Sanger sequencing using mice of known genotype, and by comparing results with a previous two-step method that used PCR amplification followed by gel electrophoresis. In addition, we clarified inconsistencies in published sequences, updated numbering to current reference sequences, and confirmed the continued presence of the mutations in the colony. It is expected that a wider availability of these models and a more efficient genotyping protocol will advance studies of the Na,K-ATPase and its cardiotonic steroid receptor.

Abstract We conducted a pilot study to determine if the BinaxNOW rapid antigen test can detect SARS-CoV-2 antigen in saliva, in place of the specified nasal (Nares) swab sample. A nasal swab may not provide an optimal sample for detecting Omicron, now the predominant variant, because Omicron sheds a greater viral load into saliva than into the nasal passages. Saliva was obtained from non-infected donors, spiked with varying concentrations of heat-denatured SARS-CoV-2 virus, and tested using the BinaxNOW kit following the manufacturer’s instructions. The BinaxNOW test detected COVID-19 in saliva samples with a Limit of Detection (LOD) of 178 TCID50/mL saliva, which was the lowest concentration tested. This detection sensitivity is comparable to the LOD reported by the manufacturer for BinaxNOW (140.6 TCID50/mL) using nasal samples. This result shows that the BinaxNOW test can detect SARS-CoV-2 in saliva with a detection power comparable to that obtained using nasal swab samples.