Phenol Red Dextrose Broth - BioReagent

Cat. No.: P1528320

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Overview

For glucose decomposition test

Specifications

Specifications & Purity

BioReagent

Storage

Room temperature

Shipped In

Normal

Grade

BioReagent

Product Line

biological_products

Application Protocols

Phenol Red Dextrose Broth fermentation test (general protocol; literature)

1. Medium preparation

• Weigh the dehydrated medium according to the label or CoA-specified grams per liter (Not specified for this item; refer to CoA/Spec Sheet). Dissolve in high-purity water with gentle heat.
• Adjust pH to ~7.2–7.4 at 25 °C (as required). Dispense into culture tubes; insert Durham tubes inverted if gas detection is desired.
• Sterilize by autoclaving at 121 °C for 15–20 min. Allow to cool to room temperature.

2. Inoculation

• Using aseptic technique, lightly inoculate each tube with a fresh colony or standardized inoculum. Include uninoculated and control strains (positive/negative).

3. Incubation

• Incubate at organism-appropriate temperature (commonly 30–37 °C) for 18–48 h. Inspect at 18–24 h to record early acid production.

4. Interpretation

• Yellow broth: Acid from glucose fermentation (positive). If a Durham tube contains a gas bubble, record “acid + gas.”
• No change (red/orange): Negative for acid production under test conditions.
• Pink/fuchsia: Alkaline shift, often due to peptone deamination or prolonged incubation.

5. Documentation and QC

• Record lot number, preparation parameters (g/L, pH, autoclave cycle), organism ID, incubation conditions, and results. Repeat with fresh medium if sterility control shows growth.

Note

• This protocol is provided as general guidance. Optimize conditions for your organisms and follow institutional biosafety procedures.

Biological Roles

Scope

• This section summarizes biological functions relevant to the components of Phenol Red Dextrose Broth in research workflows. It does not imply clinical or diagnostic use.

Dextrose (glucose) role (literature)

• Universal carbon/energy source: Many bacteria import glucose via PTS or permease systems and metabolize it through glycolysis and fermentation pathways.
• Acid and gas formation: Fermentation products (e.g., lactic, acetic, formic acids; CO2/H2 via formate lyase in some taxa) lower pH and may generate gas detectable in Durham tubes.

Phenol red role (literature)

• Internal pH indicator: Exhibits a yellow color under acidic conditions and red/fuchsia under neutral to alkaline pH, enabling direct readout of metabolic acid production.
• Minimal metabolic interference: At typical medium concentrations, phenol red provides a visual signal without significantly impacting growth of many bacteria.

Peptone/salts role (literature)

• Provide amino acids, peptides, and electrolytes to sustain basal growth and enzyme activity, ensuring organisms can proliferate sufficiently to express fermentation phenotypes.

Interpretation considerations (literature)

• Early yellowing indicates rapid acid production; late reversion to red may reflect consumption of acids or peptone deamination producing alkaline byproducts.
• Non-fermenters may still grow using peptones, potentially causing slight alkalinization (pink hue) over time. Include timing controls to avoid over-interpretation.

Item-specific identifiers

• Biological roles specific to this lot/formulation: Not specified for this item; refer to CoA/Spec Sheet.

Buffer Applications

Applicability

• Phenol Red Dextrose Broth is not designed as a dedicated buffer system. It is a nutrient medium with an indicator dye; any buffering capacity arises incidentally from the peptone and salts present.

Guidance (literature)

• Starting pH: Working broth is typically adjusted to near-neutral pH prior to sterilization to standardize the indicator baseline (commonly around pH 7.2–7.4).
• Do not use this medium to maintain a fixed pH under strong acid/base load; its purpose is to reveal pH changes due to microbial metabolism.
• If rigorous pH control is required, conduct experiments in a defined buffer (e.g., phosphate or MOPS) and add phenol red separately as an indicator, or use defined minimal media with known buffering systems.

Item-specific buffer parameters

• Exact pH set point and buffering constituents for this item: Not specified for this item; refer to CoA/Spec Sheet.

Green Alternatives

Context

• For culture media such as Phenol Red Dextrose Broth, "green" considerations focus on energy, water use, packaging, and waste management rather than solvent substitution.

Opportunities (general/literature)

• Energy efficiency: Batch-prepare media and autoclave at validated minimum time required for sterilization load to reduce energy consumption.
• Water stewardship: Use appropriately pure water (Type II may suffice for many routines) to balance quality with resource use; avoid unnecessary triple distillation.
• Reusable materials: Employ glass culture tubes and reusable Durham tubes to cut plastic waste; validate cleaning/sterilization cycles.
• Waste minimization: Prepare only volumes needed for the test window; promptly disinfect and dispose of spent cultures to prevent overgrowth and reduce bioburden in waste streams.
• Safer chemicals: Avoid adding sodium azide or other toxic preservatives unless required by protocol; prefer heat sterilization.

Comparison snapshot (literature)

• Phenol Red Dextrose Broth vs. alternative indicators:
  • Phenol red (current): Heat-stable, clear visual endpoint, widely documented.
  • Bromothymol blue/Andrade indicator: Alternative pH indicators; may have different pH windows and waste toxicity profiles. Selection should match the biological question and institutional EHS guidance.

Documentation

• Track media prep, lot numbers, and sterilization parameters to support right-first-time preparation and reduce remakes and associated waste.

Pharmaceutical Uses

Scope

• No therapeutic or clinical claims. The following notes concern potential roles in research and manufacturing support contexts.

General/literature applications in regulated environments

• Environmental monitoring and training: Carbohydrate fermentation broths are often used in microbiology labs for method development, staff training, and proficiency testing relevant to microbial identification workflows.
• Process development: Useful in research projects studying microbial strain carbohydrate metabolism, which can inform upstream bioprocess screening (non-GMP laboratory settings).
• QC method suitability: Indicator broths may be employed during qualification of laboratory procedures (e.g., culture viability checks) in research labs associated with pharmaceutical development.

Regulatory notes

• This product is for research use only per Product Data and is not validated for diagnostic use or as a compendial medium.
• Pharmacopeial status, if any (e.g., alignment with USP/EP monographs) is Not specified for this item; refer to CoA/Spec Sheet.

Practical considerations

• Document lot numbers and preparation parameters when used to support any method development activity.
• For GMP or compendial applications, use media specifically qualified and documented for that purpose.

Physical Properties

Item-specific facts (from Product Data)

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Physical constants (mp, bp, density, refractive index, water or metal limits): Not specified for this item; refer to CoA/Spec Sheet.

General/literature characteristics for this class of product

• Nature of material: Dehydrated, composite microbiological medium designed to be dissolved in purified water to make an aqueous broth.
• Solubility (literature): Freely soluble in water to prepare the working broth; insoluble in most organic solvents due to the complex, largely polar composition (peptones, salts, carbohydrate, dye).
• pH behavior (literature): Working broth is typically adjusted near neutral (around pH 7.2–7.4 at 25 °C) prior to sterilization; after autoclaving, minor pH drift can occur. Indicator transition for phenol red is approximately pH 6.8 (yellow) to 8.2–8.4 (red/fuchsia).
• Color (literature): Prepared broth is red/orange at neutral pH due to phenol red; turns yellow upon acid production during fermentation tests.
• Osmolality/ionic strength (literature): Governed by recipe (peptone, NaCl, carbohydrate); sufficient to support general bacterial growth and fermentation readouts; exact values are formulation-dependent.

Notes for use

• Prepare with high-purity water (Type I or II) to avoid background color shifts from impurities.
• Filter or autoclave sterilize as appropriate; phenol red is heat-stable under standard autoclave conditions used for culture media.

Quality and Grades

Item-specific facts (from Product Data)

• Grade/Purity: BioReagent.

What BioReagent grade implies (general guidance)

• BioReagent-grade materials are intended for biological and biochemical research workflows, emphasizing low contaminant levels that could interfere with microbial growth or biochemical assays. For formulated media, this typically includes consistent nutrient performance, indicator responsiveness, and low inhibitory impurities.

How this applies to Phenol Red Dextrose Broth (general)

• Consistency: Lot-to-lot reproducibility in color response (phenol red), carbohydrate content (dextrose), and growth-supporting components (peptone/salts) is critical for fermentation tests and carbohydrate utilization studies.
• Clarity and color: Upon proper dissolution and sterilization, the broth should be optically clear with a defined red/orange hue at neutral pH; deviations may indicate water quality issues or contamination.
• Sterility assurance: Product is supplied non-sterile (typical for dehydrated media). End-user sterilization (autoclaving or validated filtration, as appropriate) is required.

Specifications and CoA

• Item-specific analytical specifications (e.g., moisture content, pH of a defined reconstitution, microbial performance parameters) are Not specified for this item; refer to CoA/Spec Sheet.

Best practices

• Document lot numbers for traceability in QC testing.
• Validate performance against control organisms relevant to your assay (e.g., acid/gas producers vs. non-fermenters).

Reaction and Applications

Scope of section

• Classical organic reaction chemistry is not applicable. Instead, this section details laboratory applications in microbiology and biochemical testing.

Applications (literature)

• Carbohydrate fermentation testing: Detects acid production (and optionally gas if used with Durham tubes) from glucose fermentation by bacteria. Acid production lowers pH, turning phenol red from red/orange to yellow.
• Carbohydrate utilization studies: Compare metabolic pathways among organisms by substituting the carbohydrate source (here, dextrose is fixed) and observing growth and pH change.
• Quality control and teaching labs: Demonstrate fermentation phenotypes of Enterobacteriaceae and other taxa; differentiate fermenters vs. non-fermenters under standardized conditions.

Mechanistic notes (literature)

• Metabolically, dextrose is transported and catabolized via glycolysis; accumulation of organic acids (e.g., lactic, acetic) reduces pH. Indicator transition occurs around pH ~6.8–8.4; yellow indicates acid, red/orange indicates neutral, fuchsia indicates alkaline shift from peptone deamination.

Practical tips (literature)

• Inoculum size: Use a light, fresh inoculum to avoid overwhelming the medium and to prevent false alkalinization from heavy protein metabolism.
• Incubation: Typically 18–48 h at organism-appropriate temperatures (e.g., 30–37 °C). Prolonged incubation can revert yellow to red as acids are re-metabolized.
• Controls: Always run positive (known fermenter) and negative (non-fermenter) controls to validate performance.
• Gas detection: Include Durham tubes vertically in broth before sterilization to capture CO2/H2 when testing for gas production.

Reaction Conditions

Scope

• Interpreted here as practical preparation and incubation conditions for microbiological use, not chemical reaction conditions.

Preparation (general/literature)

• Dissolution: Suspend the dehydrated medium in purified water with gentle heating/stirring until fully dissolved. Typical use concentrations for phenol red carbohydrate broths fall in the few tens of grams per liter; exact grams per liter are Not specified for this item; refer to CoA/Spec Sheet.
• pH: Adjust to near-neutral (commonly ~7.2–7.4 at 25 °C) before sterilization to standardize indicator baseline.
• Sterilization: Autoclave at 121 °C for 15–20 min. Avoid oversterilization to limit sugar caramelization or Maillard reactions that may darken the medium.

Inoculation and incubation (literature)

• Aseptically dispense into tubes (optionally with Durham tubes for gas detection) prior to sterilization or after, as validated. Inoculate lightly with a fresh culture.
• Incubation temperature/time: Typically 18–48 h at 30–37 °C depending on the organism. Check at 18–24 h to reduce risk of reversion from acid to alkaline.

Expected outcomes (literature)

• Positive fermentation: Yellow color (acid); possible gas bubble in Durham tube.
• Negative fermentation: No color change (remains red/orange) or slight pink if alkaline metabolites arise from peptone deamination.

Controls and QC (literature)

• Include known fermenter and non-fermenter strains; verify sterility controls. Record lot numbers, prep date, pH, and sterilization cycle.

Safety and Handling

Item-specific facts (from Product Data)

• GHS classification, signal word, pictograms, H-statements: Not specified for this item; refer to SDS.
• Storage conditions: Room temperature (as supplied); shipped under normal conditions.

General safety guidance (literature)

• Phenol Red Dextrose Broth is a laboratory microbiological medium. Handle the dry powder and prepared broth using good laboratory hygiene.
• Potential hazards: Powder may cause mechanical irritation to eyes/respiratory tract. Phenol red dye may stain. Medium supports microbial growth after reconstitution—treat used broth and cultures as biohazardous.
• PPE: Lab coat, safety glasses, and appropriate gloves. Use a dust mask/respirator if handling large quantities of dry powder or if dusting occurs.
• Engineering controls: Work in a clean area; use a biological safety cabinet when inoculating or handling cultures.
• Incompatibilities: Avoid strong oxidizing agents and strong acids/bases during storage of the dehydrated medium. Keep away from moisture to prevent caking and premature degradation.

First-aid overview (literature)

• Eye/skin contact: Rinse with water for several minutes; remove contaminated clothing. Seek medical attention if irritation persists.
• Inhalation: Move to fresh air; seek medical attention if symptoms occur.
• Ingestion: Rinse mouth; seek medical advice.

Waste and decontamination (literature)

• Autoclave or chemically disinfect used broth and culture materials prior to disposal per institutional biosafety procedures. Consult the SDS for authoritative safety and disposal information.

Solvent Selection

Applicability

• This product is a dehydrated culture medium intended for aqueous reconstitution. Conventional organic solvent selection is not applicable.

Aqueous preparation (general guidance)

• Primary solvent: High-purity water (Type I or II) is recommended to minimize background color shifts and ionic contaminants that may affect microbial growth or indicator performance.
• Sterilization: Autoclaving at 121 °C for 15–20 minutes is commonly used after dissolution. Some users sterile-filter heat-labile supplements if added post-autoclave.

Water quality considerations (literature)

• Resistivity ≥ 10–18 MΩ·cm water reduces trace ions that may influence pH or microbial physiology.
• TOC and endotoxin: Keep low to avoid confounding results in sensitive organisms; although most routine fermentation tests tolerate standard laboratory DI/RO water, Type I water provides maximal consistency.

Comparison to alternatives (general)

• Phenol Red Carbohydrate Media use water exclusively. Do not substitute organic solvents; they are incompatible with microbial growth and will denature nutrient components.

Practical tips

• Degassing is unnecessary; however, ensure complete dissolution before sterilization to avoid hot spots and caramelization of sugars during autoclaving.
• If adding additional carbohydrates or supplements, dissolve in water separately and sterile-filter, then aseptically combine with cooled sterile base to preserve indicator fidelity.

Storage and Reconstitution

Item-specific facts (from Product Data)

• Storage conditions: Room temperature.
• Shipped in: Normal conditions.

Reconstitution (general/literature guidance)

• Use high-purity water to dissolve the dehydrated medium. The exact grams per liter for this specific item are Not specified for this item; refer to CoA/Spec Sheet.
• Mix with gentle heating until fully dissolved. Adjust pH to near-neutral (commonly ~7.2–7.4 at 25 °C) if required by your SOP.
• Sterilize by autoclaving at 121 °C for 15–20 minutes. Allow to cool and, if adding heat-labile supplements, aseptically add after cooling to ~45–50 °C.

Aliquoting and shelf life (literature)

• Store unopened powder tightly sealed, desiccated, and away from light at room temperature to prevent caking and dye photodegradation.
• Prepared broth: Store at 2–8 °C if not used immediately; protect from light. Use as soon as practical—extended storage can alter indicator performance. Typical in-use shelf life is laboratory- and validation-dependent.

Freeze–thaw guidance

• Do not freeze prepared broth unless validated; freezing can precipitate components and alter indicator response.

Research use note

• For research use only (as stated in Product Data). For item-specific stability and performance claims, consult the product CoA/Spec Sheet.

Structure and Identity

Item-specific facts (from Product Data)

• Product: Phenol Red Dextrose Broth (SKU: P1528320)
• Grade/Purity: BioReagent
• Storage: Room temperature; shipped under normal conditions
• CAS/InChIKey/SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula / Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.

General description (literature)

• Phenol Red Dextrose Broth is a dehydrated microbiological culture medium intended for preparation of an aqueous broth containing:
  • A nutrient/peptone base to support microbial growth
  • Dextrose (glucose) as a fermentable carbohydrate
  • Phenol red as an internal pH indicator (yellow in acidic range; red/orange near neutral; pink above neutral)
• As a formulated medium, it is a mixture, not a single defined molecule; thus, conventional single-compound identifiers (SMILES, InChI) do not apply.

Structural features (literature)

• The key functional component for readout is phenol red (a sulfonephthalein dye) that undergoes reversible protonation/deprotonation with a visible color change around pH ~6.8–8.4.
• Dextrose is a monosaccharide (D-glucose) that many microorganisms ferment to organic acids (and sometimes gas), lowering pH and triggering the indicator response.

How to visualize the 2D components (literature)

• Phenol red: triphenylmethane-derived xanthene-like core with phenolic substituents and a sulfonyl bridge; color change arises from conjugation changes with protonation state.
• Dextrose: six-membered pyranose ring (D-glucopyranose) with multiple hydroxyls in defined stereochemistry. The medium as sold is a composite powder, not a discrete molecular structure.

Synthetic Utility

Applicability

• Phenol Red Dextrose Broth is a formulated microbiological growth and indicator medium. It is not a reagent for chemical synthesis and has no conventional role in organic or inorganic transformations.

Guidance

• If your workflow requires a pH indicator in a synthetic context, use purified indicator dyes (e.g., phenol red as a standalone reagent) rather than a complete culture medium.
• For biocatalysis research where microbial metabolism is leveraged, this broth can support cell growth and provide a visual readout of carbohydrate fermentation, but product isolation or synthetic yields are not relevant endpoints for this medium.

Target Specificity

Not applicable

• This product is not an antibody, probe, or affinity reagent. It has no target specificity parameters such as antigen/epitope, clone, isotype, or species reactivity.

Item-specific data

• Any target-binding specifications: Not applicable.