Evaluation of New Saliva Collection Device for Determination of Salivary Cotinine, Cortisol, Dehydroepiandrosterone and Testosterone Concentrations

Abstract

Objectives: This study was conducted to examine the effectiveness of a new salivary collection device (φ10 mm × 25 mm) made of polypropylene and polyethylene polymers (Salisoft^®).
Method: Experiment 1; We measured the absorption capacity of the new device by two methods. Next, we examined whether the device affected the pH of 0.1 M NaHCO₃ solution (pH 8.7) and 0.1 M sodium phosphate buffer solution (pH 6.0). Experiment 2; We compared three saliva collection methods: by passive drool, using a cotton device (Salivette^®), and using the new device. Saliva samples were collected from twelve men (average age, 31.5 ± 17.1 years). Saliva samples were assayed for cotinine, cortisol, dehydroepiandrosterone, and testosterone concentrations by enzyme immunoassay, and the pH of saliva samples were measured.
Results: After this device was put in the mouth for one minute, 1.28 ± 0.13 mL (mean ± SD, N = 6) of saliva samples were obtained. The mean pHs of saliva samples collected using Salisoft^® and by passive drool did not differ significantly, whereas that of saliva samples collected with Salivette^® was significantly low. Saliva samples collected with Salisoft^® and those obtained by passive drool did not show significant differences in the concentrations of cotinine, cortisol, dehydroepiandrosterone, and testosterone. Moreover, significant positive correlations were noted between the concentrations in saliva samples collected with Salisoft^® and those in saliva samples collected by passive drool.
Conclusion: This new device was shown to be suitable for saliva collection for the determination of the concentrations of cotinine and some steroids by enzyme immunoassay.