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Periodic acid-Schiff's reagent assay for carbohydrates in a microtiter plate format

Kilcoyle, Michelle
Gerlach, Jared Q.
Farrell, Mark P.
Joshi, Lokesh
Citation
Kilcoyne, M,Gerlach, JQ,Farrell, MP,Bhavanandan, VP,Joshi, L (2011) 'Periodic acid-Schiff's reagent assay for carbohydrates in a microtiter plate format'. Analytical Biochemistry, 416 :18-26.
Abstract
Microtiter plate colorimetric assays are widely used for analysis of carbohydrates and glycoconjugates. However, mucins are often not easily detected, as they have low neutral sugar content. We have adapted and optimised the periodic acid-Schiff's reagent (PAS) staining for microtiter plate assay by examining five factors: concentration and volume of periodic acid, oxidation time, volume of Schiff's reagent, and color development time. This assay requires just 25 Mu-l of sample, utilises standardised Schiff's reagent, and has decreased assay time (140 min to completion). Seventeen monosaccharides (acidic, neutral, basic, phosphorylated, and deoxy) and four disaccharides were assessed. PAS-positive carbohydrates (amino, N-acetylamino, deoxy, and certain neutral monosaccharides, and sialic acids) responded linearly within a 10-100 nmol range approximately, which varied for each carbohydrate. The assay response for fetuin and porcine gastric mucin (PGM) was linear up to 150 mu-g (highest concentration tested), with no response from nonglycosylated protein. A lower response for asialofetuin was observed, but desialylated PGM preparations were similar or higher in response than their sialylated counterparts. The simplicity and low sample consumption of this method make it an excellent choice for screening or quantitation of chromatographic fractions containing carbohydrates and glycoconjugates, especially in the case of mucins.
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Attribution-NonCommercial-NoDerivs 3.0 Ireland