A Protein Dye-Binding Assay on Cellulose Membranes for Tear Protein Quantification

Abstract

The protein dye-binding assay we developed by using cellulose membranes or Schirmer strips is an efficient and convenient method for measuring tear protein concentration.

Interactions of enological tannins with the protein fraction of saliva and astringency perception are affected by pH

“…3, except that after dilution with either pH 7.0 or pH 3.5 water, saliva was centrifuged and aliquots of the supernatants were analyzed for protein on cellulose membranes. precipitation (López-Cisternas et al, 2007;Obreque-Slier, Mateluna, et al, 2010;. In this study, we used normalized solutions of a gallotannin-rich hydrolyzable tannin and a condensed tannin, both of which had been previously characterized by HPLC chromatography and spectral analysis Obreque-Slier, Peña-Neira, López-Solís, Ramírez-Escudero, & Zamora-Marín, 2009).…”

“…Salivary proteinetannin interactions were assessed using a recently reported protein diffusion assay and a precipitation assay (López-Cisternas et al, 2007;Obreque-Slier, Mateluna, et al, 2010;, with the following modifications.…”

“…Tanninesalivary protein interactions were assessed under in vitro conditions reflecting both the degree of dilution experienced by saliva during wine tasting and the expected pH in the wineesaliva mixture in mouth (Lagerlöf & Dawes, 1984;Müller et al, 2010). We examined the effect of two different enological tannins, a condensed enological tannin and a hydrolyzable enological tannin, on two physicochemical properties of the salivary protein, namely, the mode of diffusion on cellulose membranes and precipitation (López-Cisternas, CastilloDíaz, Traipe-Castro, & López-Solís, 2007;Obreque-Slier, Mateluna, et al, 2010).…”

Measurement of saliva volume in the mouth of members of a trained sensory panel using a beetroot (Beta vulgaris) extract

“…Human saliva is a non-homogeneous viscoelastic watery fluid with fractions differing in their rheologic properties López-Cisternas, Castillo-Díaz, Traipe-Castro, & López-Solís, 2007). Partitioning of beetroot pigments between those fractions, or between saliva and any of the various oral surfaces or materials that may be present in the mouth, might have resulted in an overestimation of the whole volume of saliva in the mouth.…”

Tannin–protein interaction is more closely associated with astringency than tannin–protein precipitation: experience with two oenological tannins and a gelatin

“…, 1969; Morcol & Subramanian, 1999). For instance, protein detection and quantification methods using solid matrices involve the fixation of the protein sample by denaturation on a nonreactive cellulose surface followed by its staining with a dye, such as Coomassie blue, that binds selectively, stoichiometrically and with high affinity to proteins (López‐Cisternas et al. , 2007; Obreque‐Slier et al.…”