Saliva sampling: Methods and devices. An overview

The continuous exchange of chemicals with blood and the non-invasive collection make saliva an interesting specimen for clinical applications, from the detection of biomarkers to the new -omic sciences in medicine. However, saliva sampling is challenging because the suitability of the collection method for the analyte of interest is either poorly investigated or, more often, not mentioned at all in most publications. This review reports a critical evaluation of the most common procedures for saliva sampling and a description of the off-the-shelf sampling devices. Their suitability for bioanalytical applications and salivary biomarkers detection, e.g. representativeness of the sample, sampling feasibility, analyte recovery, and sample amount, is discussed.