Uronic Acid Assay
Uronic Acid Assay - Related Videos
04:17
Quantification of Bacterial Alginate Using the Uronic Acid Carbazole Assay
0 Views •
2025
Source: Al Ahmar, R., et al. Culture of Small Colony Variant of Pseudomonas aeruginosa and Quantitation of its Alginate. J. Vis. Exp. (2020)This video demonstrates a colorimetric assay to quantify alginate produced by Pseudomonas aeruginosa, using carbazole to detect uronic acids after acid hydrolysis. The method enables comparative analysis of alginate production normalized to bacterial biomass in research and clinical studies.
04:04
Radiolabeled Amino Acid Uptake Assay to Quantify Cellular Uptake of Amino Acids
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2025
This video demonstrates an in vitro technique for estimating amino acid uptake by bone marrow-derived stromal cells. Na+-dependent amino acid transporters mediate the uptake of radiolabeled amino acids inside the cells, and the cellular uptake is estimated by measuring the radioactivity.
06:55
Simple Bulk Readout of Digital Nucleic Acid Quantification Assays
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Cited by 5 •
2015
We describe an endpoint digital assay for quantifying nucleic acids with a simplified (analog) readout. We measure bulk fluorescence of droplet-based digital assays using a standard qPCR machine rather than specialized instrumentation and confirm our results by microscopy.
03:35
Thiobarbituric Acid-Reactive Substances Assay to Assess Oxidative Stress in Human Serum
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2025
This video demonstrates the thiobarbituric acid reactive substances (TBARS) assay to assess oxidative stress in biological samples.
03:38
Polyprotic Acids
0 Views •
2020
Acids are classified by the number of protons per molecule that they can give up in a reaction. Acids such as HCl, HNO3, and HCN that contain one ionizable hydrogen atom in each molecule are called monoprotic acids. Their reactions with water are: Monoprotic acids: Reactions with water HCl (aq) + H2O (l) ⟶ H3O+ (aq) + Cl− (aq) HNO3 (aq) + H2O (l) ⟶ H3O+ (aq) + NO3− (aq) HCN (aq) + H2O (l) ⇌ H3O+ (aq) + CN− (aq) Even though it contains four hydrogen...
FAQs
Concentrated sulfuric acid converts uronic acids into reactive furfural derivatives through dehydration. These derivatives then react with carbazole to produce a colored complex. Because the resulting color reflects the amount of reactive uronic-acid-derived product, the chemical conversion is the essential link between sample composition and the spectrophotometric measurement.
A standard curve provides the reference needed to relate measured color intensity to uronic acid amount. Samples are compared with standards prepared to represent known values, allowing their spectrophotometric responses to be interpreted quantitatively rather than treated as simple visual color differences. This comparison supports estimation in biological samples and polysaccharide preparations.
Color intensity represents the spectrophotometrically detectable response produced after uronic acids undergo acid dehydration and carbazole complex formation. Its meaning depends on comparison with the standard curve, which converts the optical response into an estimated uronic acid content. The measurement therefore connects chemical reactivity with quantitative analysis of acidic polysaccharide-containing material.
A basic workflow includes preparing the biological sample or polysaccharide preparation, exposing it to the concentrated sulfuric acid and carbazole reaction system, measuring the developed color with a spectrophotometer, and comparing the result with a standard curve. Consistent handling across standards and samples is important because the final estimate depends on their comparable color responses.
The assay can be applied to extracellular matrix glycosaminoglycans, bacterial capsules, plant pectin, and other acidic polysaccharides. This range makes it useful across different biological materials: tissue samples can support extracellular matrix studies, microbial preparations can reveal capsule-related composition, and plant or biomaterial samples can be assessed for uronic-acid-containing polysaccharides.
In biology, the method helps estimate polysaccharide-associated uronic acids when researchers are studying tissue composition, microbial structure, plant cell walls, or biomaterial characteristics. The resulting measurement provides a composition-related readout rather than a complete structural description, so it is especially useful for comparing acidic polysaccharide content among relevant samples or preparations.