Sorbitol MacConkey Semi-Solid Medium - BioReagent

Cat. No.: S1528502

QUALITÄT & REINHEIT BioReagent

Storage

Room temperature

Shipped In

Normal

Übersicht

For O157 strain preservation

Spezifikationen

Spezifikationen & Reinheit

BioReagent

Storage

Room temperature

Verschickt in

Normal

Note

BioReagent

Product Line

Biologische Produkte

Application Protocols

General laboratory protocol for Sorbitol MacConkey Semi-Solid Medium (literature guidance; adjust to your SOP and CoA):

1. Preparation

• Weigh the dehydrated medium per manufacturer’s instructions (Not specified for this item; refer to CoA/Spec Sheet).
• Suspend in purified water with stirring; gently heat to dissolve completely. If required by your method, adjust pH at room temperature.
• Sterilize by autoclaving (e.g., 121 °C for 15 min; literature). Avoid overheating to preserve dye integrity.

2. Dispensing and Solidification

• Dispense aseptically into sterile tubes (e.g., 5–7 mL per 16×125 mm tube, as suited to your method). Allow to solidify upright to create a uniform semi-solid column.

3. Inoculation

• Using a sterile straight needle, stab-inoculate centrally to approximately two-thirds depth. Optionally, lightly streak the surface for additional colony morphology/color assessment.
• Include positive and negative control strains for motility and sorbitol fermentation.

4. Incubation and Interpretation

• Incubate at 35–37 °C for 18–24 h (extend to 48 h if needed).
• Read motility as diffuse growth radiating from the stab line; read fermentation as pink/red zones around growth (neutral red). Non-fermenters remain colorless/pale with growth confined to the stab.

5. Quality checks

• Verify sterility controls; document lot number, pH, and performance controls per SOP.

All steps are general; follow the specific quantities/parameters on the CoA/Spec Sheet for SKU S1528502.

Biological Roles

While the medium itself has no biological role, it is designed to probe microbial physiology and metabolism in research settings (literature/general):

• Carbon metabolism: Sorbitol serves as the carbon source to assess the presence and regulation of sorbitol transporters and dehydrogenases in Gram-negative bacteria. Observable acidification indicates active fermentation pathways.
• Selective pressure: Bile salts and crystal violet exert selective inhibition against Gram-positive organisms, modeling enteric-like conditions and enriching for Enterobacteriaceae and other Gram-negative rods.
• pH response: Neutral red reports acid production by changing color around fermenting colonies or along motility tracks in semi-solid matrices, coupling metabolic readouts to spatial growth patterns.
• Motility behavior: Semi-solid gel (reduced agar) enables visualization of flagella-driven motility and chemotaxis, allowing investigators to distinguish motile vs. non-motile strains under selective/differential constraints.
• Phenotypic profiling: Combined with orthogonal tests (e.g., citrate utilization, indole production), researchers can construct metabolic/physiological fingerprints useful in taxonomy, strain characterization, and process monitoring (non-clinical).

Note: Exact component concentrations and performance parameters for SKU S1528502 are Not specified for this item; refer to CoA/Spec Sheet for lot-specific details.

Buffer Applications

This product is not a dedicated buffer; however, many MacConkey-type formulations incorporate buffering capacity (e.g., phosphates) to stabilize pH during fermentation assays (literature/general). Practical notes:

• Intended use: Differential/selective culture with indicator response, not precision pH buffering.
• pH management: If pH drift undermines indicator performance, prepare medium with freshly produced purified water, avoid CO2 absorption during cooling, and equilibrate to room temperature before inoculation. Verify pH after sterilization when method SOPs require it.
• Alternative buffers: For experiments requiring strict buffering without selectivity or dyes (e.g., enzyme assays), use defined buffers (e.g., phosphate, MOPS) and perform microbial growth assays separately.

For SKU S1528502, item-specific pH targets and buffering components are Not specified for this item; refer to CoA/Spec Sheet.

Green Alternatives

This product is inherently aqueous and solvent-free in use, aligning well with green chemistry principles for reduced volatile organic compounds (VOCs). Considerations and alternatives (literature/general):

• Environmental profile:
  • Aqueous preparation; no organic extraction or hazardous solvent waste.
  • Low-temperature processing aside from brief autoclaving minimizes energy consumption in routine use.
• Waste minimization:
  • Prepare only the required volume; unused prepared medium has limited shelf life. Smaller batch preparation reduces autoclave cycles and waste.
  • Solidify and autoclave spent media before disposal; segregate biohazard waste per local regulations.
• Alternative media choices:
  • Chromogenic/fluorogenic media can reduce incubation/confirmation steps (fewer plates/tubes), but may include specialty dyes with different environmental profiles.
  • Non-dye selective broths minimize dye disposal but may require secondary differential assays.

Comparison (general):

• Semi-solid sorbitol MacConkey vs. solid plates
  • Resource use: Semi-solid tubes can be capped and stored longer with reduced desiccation; plates facilitate high-throughput streaking but generate more single-use plastic.
  • Data quality: Semi-solid supports motility plus fermentation in one test, potentially reducing the number of separate media required.

No item-specific environmental certifications are claimed; consult institutional green lab policies for best practices.

Pharmaceutical Uses

Not an excipient or therapeutic agent. In pharmaceutical research and manufacturing environments, sorbitol MacConkey semi-solid media may be used in non-clinical contexts such as:

• Microbiological research studies on enteric Gram-negative organisms (selectivity and sorbitol fermentation) to support method development and in-house training.
• Process/environmental monitoring method development and microbial characterization research in QC laboratories (non-clinical), where phenotypic differentiation and motility assessment are of interest.
• Strain banking and phenotypic verification workflows (research use only) where semi-solid consistency aids motility checks alongside carbohydrate utilization.

No pharmacopeial monograph is claimed for this specific SKU. Always validate media performance according to your internal SOPs and relevant compendial guidance when used to support regulated workflows. Research Use Only.

Physical Properties

Item-specific physicochemical constants (bp, mp, density, refractive index) are not defined for complex dehydrated media blends.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet. (Literature: dehydrated medium typically a free-flowing powder; prepared medium forms a low-gelling semi-solid.)
• Solubility: Readily dispersible in water (literature, for typical MacConkey-type media); organic solvents are not used for preparation.
• pH (literature, typical): Prepared MacConkey-type media are commonly adjusted to pH ~7.1 ± 0.2 at 25 °C before sterilization; final pH can shift slightly after autoclaving. Semi-solid consistency is achieved by lowering agar to ~0.3–0.5% w/v (literature), enabling motility assays while retaining matrix integrity.
• Color (literature, typical): Dehydrated powder often tan to pinkish; hydrated gel is light pink to red due to neutral red indicator, becoming colorless/yellow locally upon acidification by fermentation.
• Stability (general): Dry medium is stable at room temperature in a tightly sealed container protected from moisture and light. Prepared plates/tubes are typically stable for short-term refrigerated storage (2–8 °C) if protected from dehydration (literature guidance).

For lot-specific appearance and pH targets used by Aladdin Scientific for this SKU, see the CoA/Spec Sheet. Do not treat the above literature values as specifications.

Quality and Grades

• Grade: BioReagent — suitable for general biological and microbiological research workflows. This grade emphasizes consistent performance in culture and differentiation assays, with attention to raw material selection and batch-to-batch reproducibility. It is not a clinical/diagnostic grade and is not certified for therapeutic applications.
• What BioReagent means in practice:
  • Sourcing and blending tailored for lab research use (media performance, selectivity, and indicator response).
  • Packaged to minimize moisture ingress and preserve dye activity and nutrient stability.
  • Supported by a CoA/Spec Sheet for lot-specific performance attributes (e.g., pH after preparation, growth promotion/selectivity tests if applicable).
• Item-specific attributes: Exact composition, color characteristics, and any in-house performance criteria for SKU S1528502 are Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/antimicrobials: None should be present in dehydrated media beyond the intended selective agents (literature note). No preservatives are added post-preparation; sterility is maintained by autoclaving and aseptic handling.
• When to choose this product: Use when a Sorbitol MacConkey semi-solid formulation is required to combine Gram-negative selectivity, sorbitol fermentation differentiation, and low-agar motility assessment in a single format for research or QC in-process checks (non-clinical).

Reaction and Applications

Chemical reaction chemistry is not the use case for this product. Instead, it serves as a selective/differential growth medium in microbiology. Below are research applications (literature/general):

• Selective cultivation of Gram-negative enteric bacteria: Bile salts and crystal violet inhibit most Gram-positive organisms, enriching for Enterobacteriaceae and related Gram-negative rods.
• Differential detection of sorbitol fermentation: Sorbitol replaces lactose as the principal carbohydrate. Fermentation produces acid that shifts the neutral red indicator, yielding pink/red zones; non-fermenters remain colorless/pale.
• Semi-solid motility assessment: Reduced agar concentration enables visualization of bacterial motility as diffuse growth radiating from the inoculation line in tubes/deeps, while also capturing fermentation halos.
• Workflow integration: Useful in environmental/food microbiology research and process QC studies (non-clinical) where distinguishing sorbitol-fermenting strains and motility traits is desirable.
• Combinatorial phenotyping: When used alongside complementary media (e.g., TSI/MIU or Simmons citrate), users can build multi-parameter phenotypic profiles.

Tip (general): Ensure inoculum standardization and consistent incubation temperatures (commonly 35–37 °C) to avoid false differentials from pH drift or gel softening. Avoid excessive condensation, which can blur motility boundaries and chromogenic contrasts.

Reaction Conditions

Classical reaction-condition guidance does not apply. Instead, the relevant “conditions” are incubation and culture parameters (literature/general):

• Reconstitution: Dissolve the dehydrated medium in purified water with gentle heating and stirring until fully solubilized; adjust pH if required by your SOP; sterilize by autoclaving.
• Dispensing for semi-solid use: Pour into sterile tubes or deeps to a consistent depth to standardize oxygen gradients; allow to solidify upright.
• Inoculation: Stab inoculate centrally using a straight needle for motility assessment; overlay inoculum on the surface if surface growth/fermentation halos are also evaluated.
• Incubation: Commonly 35–37 °C for 18–24 h; extend to 48 h if differentiation is weak (per laboratory method). Avoid temperatures that soften the gel.
• Readout: Motility appears as diffuse turbidity radiating from the stab; sorbitol fermentation yields a pink/red color shift around growth (neutral red response). Non-fermenters remain colorless/pale.
• Controls: Include known sorbitol fermenter and non-fermenter strains to verify selectivity and indicator performance each batch.

All values are general literature guidance; item-specific validated conditions for SKU S1528502 are Not specified for this item; refer to your lab’s method validation and the CoA/Spec Sheet.

Safety and Handling

• GHS classification, pictograms, signal word, and H-statements: Not specified for this item; refer to the current SDS for SKU S1528502.
• General hazards (literature/Good Lab Practice): Dehydrated culture media may cause mechanical irritation to eyes/respiratory tract as dust; avoid inhalation and contact. Components may include dyes and bile salts that can irritate skin or eyes. Not for human or animal consumption. For research use only.
• PPE: Wear lab coat, safety glasses, and appropriate gloves. Use a dust mask/respirator if handling large quantities or if dust generation cannot be controlled. Work in a biosafety cabinet when handling inoculated media or potentially pathogenic cultures.
• Incompatibilities (general): Avoid moisture uptake and contamination; store away from strong oxidizers and acids/bases that could degrade indicator dyes or nutrients. Do not mix with disinfectants or biocides prior to use.
• Sterilization: Prepare with purified water and sterilize by autoclaving per your lab’s biosafety SOPs. Allow to cool to appropriate pouring temperature before dispensing.
• Biological risk: Once inoculated, the medium constitutes biohazardous waste. Autoclave all used media and materials before disposal according to institutional and regulatory requirements.
• First aid (overview): If inhaled, move to fresh air; if on skin/eyes, rinse with water; if ingested, rinse mouth. Seek medical attention if symptoms persist. Always defer to the SDS for authoritative safety and first-aid information.

Solvent Selection

This product is a microbiological medium formulated for aqueous preparation only; organic solvent selection is not applicable.

• Preparation solvent: Water (purified/deionized). Use freshly produced, low-conductivity water to minimize interference with indicator dyes and selectivity (general guidance).
• Typical practice (literature): Dissolve the dehydrated medium in water with gentle heating and stirring; adjust pH if required; sterilize by autoclaving. For semi-solid performance, the agar concentration is preset in the dehydrated blend; do not dilute unless your method validates the final gel strength.
• Comparison to alternatives:
  • MacConkey (lactose) vs. MacConkey (sorbitol): Sorbitol variant differentiates sorbitol fermenters among Enterobacteriaceae; lactose variant differentiates lactose fermenters. Choose based on the target metabolic trait under study.
  • Semi-solid vs. solid: Semi-solid supports motility assays; solid plates favor colony isolation and differentiation by colony morphology and color.

For detailed water quality requirements or pH adjustments validated for SKU S1528502, consult the CoA/Spec Sheet and your laboratory SOPs.

Storage and Reconstitution

• Storage (as supplied): Room temperature (per Product Data). Keep tightly closed in original container. Protect from moisture, heat, and direct light.
• Shipping: Normal (per Product Data).
• Shelf life: Not specified for this item; refer to CoA/Spec Sheet.

Reconstitution and use (literature/general; not item specifications):

• Water quality: Use freshly prepared purified/deionized water. Avoid high chloride/carbonate content that can affect indicator and selectivity.
• Dissolution: Add the specified mass of dehydrated medium to water (Not specified for this item; refer to CoA/Spec Sheet). Warm gently with stirring until fully dissolved. Minimize foaming.
• pH: Check and adjust as required by your SOP after dissolution and before sterilization.
• Sterilization: Autoclave using a validated cycle (e.g., 121 °C, 15 min). Do not over-autoclave to preserve dye and carbohydrate integrity.
• Dispensing: For semi-solid use, dispense into tubes/deeps and allow to solidify upright. Avoid condensation.
• Prepared medium storage: Store finished tubes/plates at 2–8 °C in the dark, sealed to prevent desiccation. Typical in-lab holding time is limited (days to a few weeks) depending on container and sealing; verify with your SOP. Bring to room temperature before inoculation to prevent water droplet formation.
• Freeze–thaw: Do not freeze prepared agar media; freezing disrupts gel structure and indicator performance.

Always consult the CoA/Spec Sheet for SKU S1528502 for exact preparation quantities and any lot-specific recommendations. Research use only.

Structure and Identity

This product is a prepared/dehydrated microbiological culture medium blend formulated for selective/differential growth studies, not a single defined molecule.

• Item type: Complex medium blend (mixture of multiple components; not a discrete compound)
• Molecular formula: Not applicable to mixtures; Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not applicable to mixtures; Not specified for this item; refer to CoA/Spec Sheet.
• SMILES/InChI/InChIKey: Not applicable for mixtures; Not specified for this item; refer to CoA/Spec Sheet.
• Structural features (general/literature): Sorbitol MacConkey media are typically based on the MacConkey formulation with bile salts and crystal violet for Gram-negative selection, sorbitol as the primary fermentable carbohydrate (replacing lactose), and neutral red as a pH indicator. Semi-solid variants include a reduced agar concentration to permit assessment of bacterial motility in addition to carbohydrate fermentation.
• 2D (descriptive): As a powder, the product comprises a heterogeneous blend of low-molecular-weight salts, peptones/complex nutrients, dye indicator, and agar gelling agent (semi-solid use). In the hydrated/sterilized state, it forms a uniform, translucent gel of low firmness suitable for stab or deep inoculation.

Note: Exact composition and concentrations can vary by manufacturer and lot; consult the product CoA/Specification for definitive composition details for SKU S1528502.

Synthetic Utility

This item is not a chemical reagent for synthesis and has no direct use in organic or inorganic reaction chemistry.

• Not applicable: It is a complex culture medium for microbial growth/differentiation, not a building block, catalyst, or solvent.
• For chemical synthesis needs: Select appropriate pure reagents/solvents with defined specifications instead. Media components (peptones, salts, dyes) are not intended for synthetic transformations.

Refer to the Reaction & Applications and Application Protocols sections for guidance relevant to microbiology workflows.

Target Specificity

This section is intended for antibodies/affinity reagents and does not apply to culture media.

• Not applicable: No antigen/epitope, clone, isotype, or species reactivity is defined for this product.