SARS-CoV-2 Detection in Saliva Using Bead Beating Homogenization and an RT-PCR Test Kit

With over 14.8 million individuals infected in the United States since March 2020, there has been a significant need for the development of additional modalities to assist in removing some of the stress placed on the supply chain [1]. Currently, the most widely used test for SARS-CoV-2 is nasopharyngeal swab-based PCR detection [1]. Whilst the sensitivity and specificity of this method is considered upward of 95 % in both categories [1], many view the sample collection as invasive and uncomfortable, reducing the number of individuals willing to get tested. This reluctance to be tested has the potential to greatly hinder public health responses. 

The use of saliva sampling for subsequent testing has been proposed as a more pleasant sample collection experience, while maintaining similar levels of sensitivity and specificity. Recently published articles show the utility of the Omni Bead Ruptor Elite™ bead mill homogenizer in homogenizing saliva samples for effective PCR based SARS-CoV-2 detection [2]. Using the Omni Bead Ruptor Elite bead mill homogenizer and a commercially-available SARS-CoV-2 RT-PCR detection kit, we have demonstrated an 100 % agreement in detecting SARS-CoV-2 from saliva in samples with recently confirmed SARS-CoV-2 infections as detected by standard nasopharyngeal swab PCR methods.

Table 1: Average Cq values and standard deviation from SARS-CoV-2 N1/N2 gene amplification from the SARS-CoV-2 confirmed positive saliva samples. 30 total samples were used in this calculation, all of which had the N1/N2 gene and the PCR internal control positive with RT-qPCR.