DNS Reagent (Ghose Method) - BioReagent, Ready-to-use

Cat. No.: D1528829

GRADE & PURITY BioReagent, Ready-to-use

Synonyms

Reducing Sugar Assay Reagent

Storage

Protected from light,Room temperature

Shipped In

Normal

Application

Cell Metabolism

Overview

The carbon nutritional status and quality traits of plants are often assessed using sugar content as an important indicator. Monosaccharides and certain oligosaccharides (e.g., maltose) contain free aldehyde or ketone groups and possess reducing properties, thus they are classified as reducing sugars. Polysaccharides and sucrose, among others, are non-reducing sugars. Taking advantage of the fact that polysaccharides can be hydrolyzed by acid into monosaccharides, the total sugar content can be determined by measuring the monosaccharide content after hydrolysis.

DNS Reagent (Ghose Method) is prepared from sodium hydroxide, 3,5-dinitrosalicylic acid, potassium sodium tartrate, phenol, etc., with a DNS concentration of 6.3 g/L. It is a component of the plant total sugar and reducing sugar detection kit (nitrosalicylic acid method). The detection principle is that reducing sugars are oxidized to sugar acids under alkaline conditions, while 3,5-dinitrosalicylic acid is reduced to a brownish-red amino compound. Within a certain range, the amount of reducing sugars is proportional to the color intensity of the brownish-red product. The absorbance of the brownish-red substance is measured at 540 nm, and this absorbance value exhibits a linear relationship with the reducing sugar content. The content of reducing sugars and total sugars in samples can be determined using colorimetry and a standard curve. DNS Reagent is also commonly used for the determination of enzyme activities such as pectinase, amylase, cellulase, and xylanase.

This reagent is intended for research use only and is not suitable for clinical diagnosis or other applications.

Materials Required (User-Supplied):

1.Distilled water, hydrochloric acid solution, sodium hydroxide solution

2.Scissors, homogenizer or mortar and pestle, 50 mL centrifuge tubes, centrifuge, water bath or constant temperature incubator, spectrophotometer, cuvettes

Operating Procedure (For Reference Only):

1. Extraction of Reducing Sugars:

(1) Weigh 0.5–3 g of plant sample, cut into small pieces, add approximately 3 mL of distilled water, and homogenize. Transfer the homogenate to a beaker or Erlenmeyer flask. Rinse the homogenizer 2–3 times with 12 mL of distilled water and combine the washings into the same container.

(2) Incubate in a 50°C water bath for 30 min with intermittent stirring to ensure complete extraction of reducing sugars.

(3) Transfer the precipitate and extract to a 50 mL centrifuge tube and centrifuge at 4000 × g for 5 min.

(4) Retain the supernatant. Add 20 mL of distilled water to the precipitate, mix well, and centrifuge again at 4000 × g for 5 min.

(5) Retain the supernatant. Combine the two supernatants, bring the volume to 100 mL with distilled water (extraction solution), and mix well. This serves as the reducing sugar test solution.

2. Hydrolysis and Extraction of Total Sugars:

(1) Weigh 0.5–3 g of plant sample, cut into small pieces, add approximately 3 mL of distilled water, and homogenize. Transfer the homogenate to a beaker or Erlenmeyer flask. Rinse the homogenizer 2–3 times with 12 mL of distilled water and combine the washings into the same container.

(2) Add 10 mL of 6 M hydrochloric acid solution to the container, mix well, and boil for 30 min with intermittent stirring.

(3) Spot 2 drops of the hydrolysate onto a glass slide, add 1 drop of indicator solution, and check whether hydrolysis is complete. Complete hydrolysis is indicated by the absence of a blue color.

(4) After hydrolysis is complete, cool to room temperature. Add 6 M sodium hydroxide solution to adjust the pH to 7.4. Bring the volume to 100 mL with distilled water, mix well, and centrifuge at 4000 × g for 5 min or filter.

(5) Take 10 mL of the supernatant or filtrate and bring the volume to 100 mL with distilled water to obtain a 1000-fold diluted total sugar hydrolysate (extraction solution). Take 1 mL of this total sugar hydrolysate for determination of reducing sugar content.

3. Preparation of Glucose Standard Curve:

Take clean centrifuge tubes or test tubes and proceed according to the table below. Use tube No. 0 as the blank to zero the instrument. Measure the absorbance at 540 nm. Plot the absorbance values on the y-axis against the standard concentrations (mg/mL) on the x-axis to generate the standard curve.

Reagent Added	0	1	2	3	4	5
Glu standard (1 mg/mL)	0	0.2	0.4	0.6	0.8	1
Distilled water (mL)	1	0.8	0.6	0.4	0.2	0
DNS Reagent (mL)	2	2	2	2	2.5	2
Distilled water (mL)	9	9	9	9	9.5	9
Equivalent glucose amount (mg)	0	0.2	0.4	0.6	0.8	1

Note: After adding the DNS reagent, heat in a boiling water bath for exactly 5 minutes, then remove and cool to room temperature under running tap water.

4. Determination of Reducing Sugars:

Transfer 1 mL of the prepared reducing sugar extract or total sugar hydrolysate into a test tube, add 2 mL of DNS reagent, and proceed with the same operations as described for the standard curve. Measure the absorbance of each tube at 540 nm.

Calculation:

Reducing sugar content (%):

Reducing sugar content (%) = (C × V_T) / (m × V_S) × 100 

Total sugar content (%): 

Total sugar content (%) = (C × V_T) / (m × V_S) × 100 × 10 × 0.9 C = Sugar amount determined from the standard curve (mg) V_T = Volume of the extraction solution (mL) m = Mass of the plant sample (mg) V_S = Sample volume used for the assay (mL)

Precautions:

1.Avoid repeated freeze-thaw cycles of this reagent to prevent loss of activity or efficiency. Store protected from light whenever possible.

2.Exercise caution when diluting hydrochloric acid and sodium hydroxide solutions to avoid personal injury.

3.Commercially available concentrated hydrochloric acid is typically approximately 11.6 M. It should be diluted to 6 M before use.

4.If samples cannot be assayed immediately, store at 2–8°C; they are stable for 3 days.

5.If the reducing sugar concentration of the sample is too high, dilute with distilled water and re-measure, then multiply the result by the dilution factor.

6.The total sugar calculation formula is applicable when interfering impurities are minimal and the reducing sugar content is relatively low compared to the total sugar content. The factor × 0.9 is used to account for the water consumed during hydrolysis when converting total sugars into monosaccharides.

7.For your safety and health, please wear a lab coat and disposable gloves during operation.

8.The reagent should be used as soon as possible after opening to prevent any adverse effects on subsequent experimental results.

9.This product is for research use only; any other use is strictly prohibited.

Specifications

Synonyms

Reducing Sugar Assay Reagent

Specifications & Purity

BioReagent, Ready-to-use

Stability And Storage

Store at RT long term (12 months). Store in the dark.

Storage

Protected from light,Room temperature

Shipped In

Normal

Grade

BioReagent, Ready-to-use

Product Line

Biological Products

Chemical and Physical Properties

• Sensitivity: Light-sensitive

Application Protocols

Manufacturer-validated protocols and application-specific parameters are not provided for this item. No tested applications are listed in the product data.

• Guidance
  • Refer to the Reaction & Applications and Reaction Conditions sections for general literature-based workflows for DNS/Ghose reducing sugar assays.
  • Always verify conditions (volumes, incubation times, wavelength, linear range) with small pilot experiments using standards and your sample matrix.

For detailed, item-specific instructions, consult the CoA/Spec Sheet if available.

Biological Roles

This product is an analytical reagent; it does not have intrinsic biological roles. However, it enables measurement of biochemical processes by reporting on reducing equivalents from carbohydrates (general):

• Enzymology (literature/general)

  • Used to quantify activities of glycoside hydrolases (e.g., cellulases, xylanases, amylases) by measuring release of reducing sugars from polysaccharides.
  • Supports kinetic studies (initial rates, Michaelis–Menten parameters) by following product formation.

• Biomass conversion

  • Monitors saccharification efficiency of lignocellulosic materials during pretreatment and enzymatic hydrolysis.

• Metabolic studies

  • Can be applied to track extracellular reducing sugars in microbial fermentations, provided matrix effects are controlled through appropriate blanks and standard-addition protocols.

No clinical or in vivo biological functions are claimed. For research use only (per product note).

Buffer Applications

DNS Reagent (Ghose Method) is a colorimetric assay reagent, not a buffering system. It is not typically used to maintain pH during biochemical reactions.

• Practical note
  • Perform enzymatic reactions in an appropriate buffer for enzyme stability (e.g., citrate, acetate, phosphate, citrate–phosphate, or sodium acetate at the desired pH), then aliquot to DNS reagent for endpoint quantification (general literature guidance).

Item-specific buffering capacity or intended use as a buffer is not applicable.

Green Alternatives

DNS reagents are effective but can involve strongly alkaline conditions and, in some published formulations, phenol or sulfite additives. Consider greener or safer alternatives where compatible with your analytical needs (general guidance):

• Comparison (literature/general)
  • DNS (Ghose-style)
    • Strengths: Robust signal at ~540 nm; tolerates many sample matrices; well-established for cellulase assays.
    • Tradeoffs: High alkalinity; heating step; potential inclusion of phenol/sulfite in some recipes; nitroaromatic component in waste.
  • PAHBAH (p-hydroxybenzhydrazide)
    • Strengths: High sensitivity; operates at lower alkalinity than DNS; good for microplate formats.
    • Tradeoffs: Reagent stability can be limited; hydrazide handling considerations.
  • BCA (bicinchoninic acid) reducing sugar variants
    • Strengths: Potentially less caustic; stable end-point purple complex.
    • Tradeoffs: More sensitive to interfering species; less standardized for cellulase metrics.
  • Nelson–Somogyi (arsenomolybdate) or phenol–sulfuric acid
    • Strengths: Broad carbohydrate detection; no nitroaromatics in the chromogen.
    • Tradeoffs: Uses strong acids; arsenic-containing reagents (Nelson–Somogyi) raise EHS concerns.

Operational “greening” within the DNS approach

• Minimize volumes via microplate formats to reduce hazardous waste.
• Validate phenol-free formulations where acceptable for your method.
• Implement proper neutralization/segregation of alkaline waste and consult EHS before disposal.

Item-specific eco/safety attributes (e.g., phenol-free) are Not specified; refer to CoA/Spec Sheet.

Pharmaceutical Uses

This is a laboratory research reagent intended for analytical quantitation of reducing sugars. It is not an excipient and has no compendial pharmaceutical use specified.

• Regulatory note

  • For research use only (as provided). Not for human or veterinary use, diagnostic procedures, or clinical applications.

• Process utility (general)

  • May be used in R&D quality control labs to profile saccharide-containing process streams or enzyme preparations; any GMP/GLP deployment would require internal qualification and method validation.

No pharmacopeial status or formulation role is specified for this item.

Physical Properties

This listing is a formulated reagent solution; a single set of compound-specific physicochemical constants does not apply.

• Item-specific properties

  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Density, refractive index, pH, viscosity: Not specified for this item; refer to CoA/Spec Sheet.
  • Solubility profile: Aqueous formulation; miscible with water by design. Exact miscibility/compatibility limits with organic solvents are not specified for this item; refer to CoA/Spec Sheet.

• Typical literature characteristics of DNS assay reagents (general, not item-specific)

  • Medium: Aqueous, strongly alkaline due to inclusion of base (commonly NaOH) to enable redox of DNSA; typical pH often >12 (literature).
  • Stabilizers: Many published formulations include sodium potassium tartrate (Rochelle salt) to stabilize the reduced chromophore and enhance color development; some variants include sulfite or phenol (literature).
  • Spectral feature: Reaction product exhibits an absorption maximum around 540 nm; exact λmax can vary slightly with formulation and matrix (literature).
  • Thermal behavior: Color development requires heating (e.g., boiling water bath); upon cooling and dilution, absorbance is read at ~540 nm (literature).

Any quantitative physical constants (bp/mp/logP, etc.) are not meaningful for a multicomponent aqueous reagent and are not specified for this item; consult the SDS/CoA for definitive information relevant to handling and instrument setup.

Quality & Grades

• Item-specific grade

  • Grade/Purity: BioReagent (as provided). BioReagent grade indicates suitability for common biochemical and molecular biology workflows, with attention to background absorbance, contaminant levels impacting enzyme assays, and lot-to-lot consistency. Exact acceptance criteria (e.g., UV background, metal content, DNSA assay performance) are Not specified for this item; refer to CoA/Spec Sheet.

• What BioReagent typically means (general)

  • Prepared from components suitable for biological assays.
  • Formulation clarity, color stability, and baseline A540/A blank are controlled to minimize background in reducing-sugar determinations.
  • Filtration/particulate control to protect spectrophotometer cuvettes and microplates.

• Stabilizers and additives

  • Presence/absence of stabilizers (e.g., tartrate, sulfite) or potential phenol content is Not specified for this item; refer to CoA/Spec Sheet.

• Documentation and lot traceability

  • For regulated or method-critical work (e.g., cellulase activity per IUPAC/Ghose), verify lot-specific performance by reviewing the CoA and, if needed, performing a glucose standard curve qualification on receipt.

• Practical guidance

  • Use matched blanks prepared with the same matrix as samples.
  • Record lot numbers in data packages to ensure reproducibility across studies.

Reaction & Applications

• Primary application (literature/general)

  • Quantification of reducing sugars (e.g., glucose, cellobiose, xylose) by reduction of 3,5-dinitrosalicylic acid under alkaline, heated conditions to form 3-amino-5-nitrosalicylic acid, measured at ~540 nm.
  • Widely used in biomass saccharification studies, enzymology (cellulase, xylanase, amylase assays), and monitoring of carbohydrate-active enzyme reactions. The Ghose method (IUPAC, 1987) standardizes conditions for cellulase activity determinations (FPase, CMCase) using DNS colorimetry.

• Reaction notes (general)

  • The reaction proceeds via electron transfer from the open-chain aldehyde/ketone forms of reducing sugars to the nitro group(s) of DNSA in strong base with heat. Stabilizers (e.g., tartrate) enhance color stability post-reduction.
  • The response is approximately proportional to reducing-end equivalents; molar absorptivity varies among sugars. Calibrate with the specific analyte when possible; otherwise, glucose standards are typically used and results reported as “glucose equivalents.”

• Practical tips (general)

  • Use matched glass culture tubes or sealed microplate protocols compatible with boiling water baths or dry-block heaters.
  • Include blanks containing all components except analyte to correct for reagent and sample matrix background.
  • Cool thoroughly and, where applicable, dilute to a defined final volume before reading A540 to minimize temperature-dependent absorbance drift.
  • Avoid strong oxidants/reductants in samples (e.g., bisulfite, ascorbate) that can bias results; assess via spike-recovery.

Manufacturer-provided specific applications are not listed for this item; users should adapt standard DNS/Ghose workflows to their system and verify linear range and precision experimentally.

Reaction Conditions

No item-specific protocols are provided. Below are general literature conditions for DNS/Ghose reducing sugar assays; adapt and validate for your system.

• Typical workflow (literature/general)

  • Standards: Prepare glucose standards spanning the expected range (e.g., 0–2.0 mg/mL or as appropriate for your spectrometer pathlength).
  • Reaction: Mix sample or standard with DNS reagent at a defined ratio (commonly 1:1 v/v in tube assays; microplate formats may differ).
  • Heating: Incubate in a boiling water bath or dry block for ~5–10 min to develop color; avoid sealed tubes that could pressurize.
  • Stabilization/Dilution: Cool to room temperature; many protocols dilute to a fixed final volume with water (or tartrate solution depending on formulation) to stabilize color and normalize pathlength.
  • Readout: Measure absorbance at ~540 nm against a reagent blank. Construct a standard curve and interpolate sample concentrations, applying appropriate dilution factors.

• Performance considerations

  • Linearity: Verify linear range with your matrix; high sugar loads may require dilution.
  • Interferences: Strong reductants (e.g., bisulfite, ascorbate) and colored/turbid matrices can bias A540; use matrix-matched blanks and spike-recovery tests.
  • Replicates: Run at least duplicates/triplicates to estimate precision.

These conditions are provided as general guidance only and are not specifications for this item.

Safety & Handling

• GHS classification and hazard statements

  • Signal Word: Not specified for this item; refer to SDS.
  • H-Statements: Not specified for this item; refer to SDS.
  • Pictograms: Not specified for this item; refer to SDS.

• General safety considerations for DNS-type reagents (literature/general)

  • Alkalinity: Typical formulations contain strong base (e.g., NaOH) and are corrosive to eyes/skin. Wear appropriate PPE: lab coat, chemical-resistant gloves (e.g., nitrile), and splash goggles/face protection.
  • Reducing environment: The assay involves heating; conduct reactions in heat-resistant tubes with loose caps to prevent pressure buildup. Use a fume hood to minimize exposure to vapors/aerosols and to any phenolic additives if present in the formulation.
  • Incompatibilities: Avoid contact with acids (vigorous neutralization/heat), oxidizers/reducers not intended for the assay, and reactive metals. Do not autoclave closed containers.
  • Spill/first aid (overview; defer to SDS for procedures): For small spills, absorb with inert material while wearing PPE; neutralize cautiously if trained. In case of skin/eye contact, rinse with copious water for ≥15 min and seek medical attention. If inhaled, move to fresh air; if ingested, do not induce vomiting; obtain medical assistance.
  • Waste: DNS assay waste can contain high alkalinity and nitroaromatics; collect as hazardous chemical waste following institutional and local regulations. Avoid drain disposal unless specifically permitted by EHS.

Always consult the product SDS for authoritative hazard classification, exposure limits, and emergency measures.

Solvent Selection

This is an aqueous, ready-to-use colorimetric reagent. Traditional solvent selection paradigms (choosing a reaction solvent) are not directly applicable.

• Polarity and miscibility

  • Water-based formulation; fully miscible with water (item-specific composition not disclosed). Compatibility with organic cosolvents (e.g., ethanol, DMSO) can affect color yield and background; if matrix contains organics, validate with standards prepared in the same matrix (general guidance).

• Use context

  • Designed to react with reducing sugars in aqueous or partially aqueous sample matrices. For highly nonaqueous samples, consider pre-dilution or extraction into aqueous buffers, then apply the reagent.

• Comparison to alternatives (general)

  • DNS vs PAHBAH or Nelson–Somogyi: DNS is robust to many sample impurities and provides a strong 540 nm signal; alternatives may be less caustic or more selective but can be more sensitive to matrix interferences.

For this specific item, any recommended diluents or compatibility notes are Not specified; refer to the CoA/Spec Sheet and SDS. When in doubt, run spike-recovery controls with your sample matrix.

Storage & Reconstitution

• Storage conditions (item-specific)

  • Store at 2–8°C (as provided).
  • Shipped on wet ice to maintain reagent integrity during transit.

• Stability and handling (general)

  • Protect from prolonged exposure to elevated temperatures and direct light to minimize baseline drift or component degradation.
  • If crystals or precipitate form during cold storage, warm gently to ambient temperature and mix to redissolve before use; do not overheat. Filter through a low-protein-binding 0.45 µm membrane if particulates persist (general guidance).

• Reconstitution

  • This product is supplied as a ready-to-use reagent; no reconstitution is specified for this item. If concentration adjustments or dilutions are needed for specific microplate formats, validate performance after any modification.

• Freeze–thaw

  • Avoid freezing unless explicitly recommended on the CoA/Spec Sheet; repeated freeze–thaw cycles can lead to component precipitation or performance drift.

Always refer to the product CoA/Spec Sheet and SDS for lot-specific stability and handling recommendations.

Structure & Identity

This product is a formulated, ready-to-use colorimetric reagent for quantifying reducing sugars by the classic dinitrosalicylic acid (DNS) assay per the Ghose method (IUPAC, 1987). It is a mixture; a single molecular identity does not apply.

• Item-specific identifiers

  • CAS: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.
  • InChIKey / SMILES: Not applicable to the formulated mixture.

• Key functional component (literature/general)

  • The chromogenic agent in DNS reagents is typically 3,5-dinitrosalicylic acid (DNSA), an aromatic carboxylic acid bearing two nitro groups (positions 3 and 5) and a phenolic OH at position 2 on a salicylic acid framework.
  • Upon reaction with reducing sugars under alkaline, heated conditions, DNSA is reduced to 3-amino-5-nitrosalicylic acid, producing an orange-red chromophore with strong absorbance near 540 nm (literature).

• Structural description of the chromophore (literature/general)

  • 2-hydroxybenzoic acid ring substituted with –NO2 groups at C3 and C5. Functional groups: phenol, carboxylic acid (present as salts in alkaline medium), and nitro groups (one of which is reducible under assay conditions). No stereocenters.

Note: Composition details (e.g., DNSA concentration, alkali, stabilizers, tartrate content) are not specified for this item; consult the product CoA/Spec Sheet for exact formulation.

Synthetic Utility

As a formulated analytical reagent, this product is not a synthetic building block. Its value in synthetic workflows is indirect, providing rapid, colorimetric readouts of reducing sugar content to guide process optimization (general):

• Carbohydrate chemistry support (literature/general)

  • Monitor hydrolysis of glycosidic bonds during acid/base catalysis or enzymatic treatments.
  • Track deprotection steps that unveil reducing ends.
  • Assess progress in biomass pretreatment strategies aimed at increasing fermentable sugar yield.

• Retrosynthetic planning aid

  • Use DNS measurements to choose reaction conditions that minimize sugar degradation (e.g., HMF formation) by balancing conversion vs. overreaction.

• Practical notes

  • Calibrate with the target sugar when possible; if not, report as “glucose equivalents.”
  • Validate that solvents/reagents from synthetic steps (e.g., residual borohydride, sulfite, ascorbate) do not interfere via non-specific reduction of DNSA.

Item-specific reaction-promoting properties are not applicable.

Target Specificity

Not applicable. This product is a chemical reagent, not an antibody or affinity reagent. There is no antigen/epitope specificity, clone, isotype, or species reactivity associated with its use.