The integrated Saliva Collection, Processing, Stabilization and Storage (iSCPSS) System

Abstract

Objective: Salivary transcriptomic and proteomic biomarker profiles have been proven to detect oral and other systemic diseases; however, current standard operation procedure (SOP) limits saliva samples and disease variety to research facilities. The universal iSCPSS System provides simultaneous self-collection of RNA and protein collection, processing, stabilization and storage at ambient temperature.

Method: The iSCPSS system (collection pad and filter unit) is optimized for RNA and protein elution through total RNA and protein analysis. To verify biomarker integrity during ambient temperature shipping, RT-qPCR and ELISA were used to quantify selected transcriptomic targets [glyceraldehyde 3-phosphate dehydrogenase (GAPDH), -Actin, ribosomal protein S9 (RPS9), and interlukin-8 (IL-8)] and proteomic target [IL-8] incubated at room temperature for 14 days compared with SOP.

Result: RT-qPCR revealed significantly lower mean threshold cycle (Ct) in iSCPSS samples (n=8) on day 0 for GAPDH, RPS9, and IL-8 (p < 0.05) and on day 3 for b-actin, GAPDH, RPS9, and IL-8 (p = 0.012, p = 0.004, p = 0.028, p = 0.003) compared to the SOP samples. From day 3 to 5, the mean Ct increased at a faster rate in iSCPSS conditions compared to the SOP indicating a greater loss in recovery. By day 14, the two methods converge indicating comparable transcriptomic target level. Immunoassays (n = 9) illustrated no significance (p > 0.05) average total protein and IL-8 level between the two methods across day 0, 3, 5, and 14. Results suggested that the iSCPSS system effectively collects and stabilizes total and specific transcriptome and proteome biomarkers comparable to the SOP.

Conclusion: The universal saliva collector provides a user friendly, convenient method that permits health screening for oral and other systemic diseases. The capability for the iSCPSS system to provide ambient temperature biomarker collection and processing extends salivary diagnostics to all participants will impact saliva clinical research.