Flowchart of study design to identify collection techniques that enable quantitative measures of taste gene expression.

Samples were collected from 8 volunteers using the six different methods, the RNA was extracted and analysed with the NanoDrop ND-1000 Spectrophotometer (for quantity and purity) and Bio-analyser (analysis of RNA integrity). Real-time quantitative PCR was completed on taste tissue markers and taste genes, allowing for the identification of methods enabling quantitative measures of taste gene expression.</p

Quantitative real-time PCR analysis of taste markers and receptors using the different collection techniques^a.

<p>Quantitative real-time PCR analysis of taste markers and receptors using the different collection techniques<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0152157#t003fn001" target="_blank">^a</a>.</p

Comparison of collection techniques (advantages and disadvantages) for the analysis of quantitative taste gene expression.

Comparison of collection techniques (advantages and disadvantages) for the analysis of quantitative taste gene expression.</p

Comparison of RNA quantity, purity and quality from the different collection techniques.

<p>Comparison of RNA quantity, purity and quality from the different collection techniques.</p

Taste genes analysed by quantitative real-time PCR (Taqman assay).

<p>Taste genes analysed by quantitative real-time PCR (Taqman assay).</p

Representative Lightcycler 480 amplification profiles of taste genes using the different collection techniques.

<p>Pap—Papillae biopsy (red), Che—Cheek saliva (Green), Ton—Tongue saliva (orange), Ora—Oragene kit (blue), Iso—Isohelix brush (black), Cyto—Livibrush cytobrush (purple), NTC—no template control (grey).</p