Comparison of two methods of tear sampling for protein quantification by Bradford method

Abstract

esquerdo, respectivamente. Para as amostras obtidas com STT os resultados foram 4,45mg/mL ±0,35 and 4,52mg/ mL ±0,29 para olhos direito e esquerdo, respectivamente. Diferenças estatisticamente significativas (p<0,001) foram encontradas entre os dois métodos. Nas condições em que o trabalho foi conduzido, a média da concentração proteica pelo método de Bradford das amostras obtidas através das tiras do STT foi superior à obtida com o tubo microcapilar. Os valores padrão da concentração protéica da lágrima obtida pelo método de Bradford devem ser analisados considerando-se o método de coleta da lágrima, uma vez que este interfere significativamente nos resultados obtidos.

Tear ferning test in horses and its correlation with ocular surface evaluation

“…A tear sample was collected with a microcapillary tube inserted in the lower eyelid of both eyes . Temperature and relative humidity of the air were recorded at the time of collection of each sample, using a thermohygrometer (Incoterm, model 7666.02.0.00).…”

An eye on the dog as the scientist's best friend for translational research in ophthalmology: Focus on the ocular surface

“…A microcapillary glass tube (1-10 µl) placed in contact with the inferior lacrimal lake is the most commonly reported technique to collect tear fluid. This method directly samples tear fluid by capillary action and is extensively described in humans, 182,216,220,[226][227][228][229][230][231][232][233][234][235][236][237][238][239] dogs, 183,191,[240][241][242][243] rabbits, 188,237,238,241,244 mice, 245,246 and rats. 183,202,237,247 Other direct techniques (seldom reported) involve micropipettes, 248 polypropylene tubing, 183 or polytetrafluoroethylene tubing.…”

“…41 cellulose filter paper and possess specific characteristics to promote tolerance (5-mm width × 35-mm length, 0.22-mm thick, 20-25 µm porosity, foldable extremity for ease of insertion). 249,257 In addition to their conventional use for aqueous tear assessment, Schirmer strips can retrieve tear fluid for bioanalytical purposes in humans, 182,216,219,220,228,231,258 dogs, 190,209,211,214,215,240,259 and small laboratory species. 244,260,261 For instance, Schirmer strips were used for indepth characterization of proteomics in human 173 and canine tears, 190 and can also successfully recover specific analytes such as cytokines, 200,258 clusterin, 182 and xenobiotics.…”

Dry Eye: A Protein Conformational Disease

“…It has been reported that total tear protein concentration obtained by Schirmer's strip is much higher than that with the capillary method. 42 In practical experience, sampling by strip was rapid, reliable, and without any risk to the subjects. On the other hand, the capillary tube method requires a greater precision and skill.…”