Starch Phosphorylase Activity Assay Kit (Colorimetric Method)

Cat. No.: S1522137

GRADE & PURITY BioReagent

Specifications

Specifiche e purezza

BioReagent

Grado

BioReagent

Applicazione

Enzyme activity assay

Metodo di rilevamento

Colorimetric Method

Stoccaggio e spedizione

Condizioni di conservazione di stoccaggio

Store at 2-8°C

Spedito in

Wet ice

Stabilità e conservazione

Store at 2-8℃ for 6 months.

Application Protocols

The following outlines a general colorimetric assay workflow for starch phosphorylase (literature/general). For this specific kit, exact steps, reagent identities, volumes, wavelengths, and incubation times are Not specified; refer to the instruction booklet.

General microplate protocol (template)

• Preparation: Bring all reagents to assay temperature. Prepare standards appropriate to the detection chemistry (e.g., G1P or Pi), blanks, and positive controls.
• Master mix: Combine buffer, substrate (soluble starch or malto-oligosaccharide), inorganic phosphate, and coupling reagents/color developer as required.
• Samples: Clarify lysates by centrifugation; optionally desalt to remove phosphate or small-molecule interferents.
• Initiation: Add sample (enzyme source) to wells containing master mix; mix briefly without bubbles.
• Incubation: 25–37°C; monitor kinetics over 5–20 min or incubate to endpoint per validated timing.
• Read: Measure absorbance at the specified visible wavelength for the color reagent. Use pathlength correction if comparing to cuvette-based standards.
• Analysis: Subtract blank, fit standard curve, and calculate activity (U/mL or U/mg protein). Report mean ± SD from technical replicates.

Controls and QC

• Include a no-enzyme blank and a no-substrate control.
• Verify linearity with time and enzyme amount.
• Assess matrix effects by spike-recovery in representative samples.

Documentation

• Record lot numbers, instrument settings, and plate layout for reproducibility.

Biological Roles

This kit measures activity of starch (α-glucan) phosphorylase (EC 2.4.1.1), a carbohydrate metabolism enzyme.

Biochemical function (literature/general)

• Catalyzes phosphorolysis of α-1,4-glucans (e.g., starch) to produce glucose-1-phosphate (G1P), conserving energy by forming a phosphorylated sugar without ATP expenditure.
• Operates reversibly; direction depends on concentrations of inorganic phosphate and glucan substrates/acceptors.

Physiological context (literature/general)

• In plants, plastidic (PHO1) and cytosolic (PHO2) isoforms participate in starch metabolism, remodeling glucans during diurnal cycles and development.
• In bacteria, maltodextrin phosphorylase supports carbohydrate utilization from environmental polysaccharides.
• In some systems, phosphorylase works in concert with debranching enzymes and starch synthases to maintain glucan architecture.

Assay relevance

• Measuring phosphorylase activity provides insight into carbon partitioning, enzyme regulation (e.g., allosteric effectors, phosphorylation state), and metabolic flux under different physiological conditions.

Notes

• Isoform specificity and regulatory features vary between organisms; assay conditions (pH, ionic strength, activators/inhibitors) should be optimized accordingly.
• This kit is labeled “For research use only” (per Product Data) and is intended for laboratory investigations of enzyme activity.

Buffer Applications

The product is an enzyme activity kit and includes or specifies buffers tailored to starch phosphorylase assays. Standalone buffer preparation guidance is therefore limited.

General/literature guidance for phosphorylase assays

• Working pH: Near neutral (typical literature range ~6.8–7.4). Optimal pH depends on enzyme source and isoform; verify experimentally.
• Common buffer systems: HEPES, MOPS, Tris, or phosphate buffers at 10–100 mM ionic strength, sometimes with Mg2+ or other salts depending on coupling enzymes.
• Interferences: Free inorganic phosphate or strong reducing sugars may interfere depending on detection chemistry; consider desalting or buffer exchange of samples.
• Additives: Mild detergents (e.g., 0.01% Tween-20) may reduce nonspecific adsorption in plates, but confirm compatibility with the kit’s color reagent.

Practical tips

• Equilibrate all buffers to assay temperature to minimize baseline drift.
• Use high-purity water (18 MΩ·cm) to reduce background.

For this specific item, exact buffer compositions, concentrations, and any supplied buffers are Not specified; refer to the instruction booklet/CoA.

Green Alternatives

While an enzyme assay kit is not a solvent or reagent typically replaced by a “greener” chemical, several practical steps can minimize environmental impact without affecting data quality.

Greener practices (general)

• Microplate miniaturization: Run assays in 96- or 384-well plates to reduce reagent volumes and waste per data point.
• Aqueous-only workflows: Avoid introducing organic solvents into samples; prefer aqueous extraction where feasible.
• Waste segregation: Collect chromogenic waste and phosphate-containing solutions for appropriate disposal; avoid unnecessary neutralization steps that generate salts.
• Energy efficiency: Perform incubations at ambient temperature when consistent with assay performance (verify with controls) to lower energy use.
• Reusable labware where appropriate: Use glass reservoirs/troughs for multichannel pipetting to reduce plastic waste, while ensuring no carryover.

Comparison table (general)

| Aspect | Conventional practice | Greener alternative | | --- | --- | --- | | Reaction volume | 200–1000 µL cuvette | 50–200 µL microplate | | Temperature control | Dedicated incubator | Room temp if validated | | Solvent use | Organic cosolvents for extraction | Aqueous buffers, SPE cleanup | | Replicates | Redundant repeats | DOE-based minimal replicates |

Component-specific greener substitutes (e.g., dye systems, preservatives) are kit-dependent and Not specified for this item; consult the booklet if substitutions are permissible.

Pharmaceutical Uses

This is a research-use-only enzymatic assay kit and is not a pharmaceutical product or excipient.

Potential roles in pharma/bioprocess laboratories (general)

• Biochemical screening: Evaluate inhibitors/activators of carbohydrate-metabolism enzymes in discovery research (non-clinical).
• Enzyme QC: Monitor activity during production, purification, or storage stability studies of starch phosphorylase or coupled enzymes used in biocatalysis.
• Formulation stress testing: Assess enzyme stability under different buffer compositions, temperatures, or excipient conditions as part of pre-formulation research.

Regulatory status

• Labeled For research use only (per Product Data). Not for diagnostic, therapeutic, or clinical use.
• No pharmacopeial monograph applicability to this kit as supplied.

Any claims of clinical diagnostic performance, therapeutic relevance, or cGMP suitability are outside the scope of this product.

Physical Properties

As an activity assay kit, there is no single molecular entity. Physical properties of individual components (buffers, substrates, enzymes, dyes) are not consolidated.

Item-specific physical specifications

• Appearance of components: Not specified for this item; refer to CoA/Spec Sheet.
• Refractive index, density, pKa, logP, UV/Vis cutoffs: Not applicable/Not specified for this item; refer to CoA/Spec Sheet.

General/literature expectations for colorimetric enzyme kits (for planning only)

• Matrix: Aqueous buffers (typically pH near neutral for phosphorylase activity; literature ~6.8–7.4). Exact pH and ionic strength depend on the kit and should be taken from the manual.
• Absorbance readout: Colorimetric assays commonly use visible wavelengths (e.g., 570 ± 20 nm or 620–660 nm), but the exact λmax is kit-specific. Not specified for this item; refer to the booklet.
• Temperature range for assays: 25–37°C (literature) with enzyme-specific optimization.

Practical notes (general)

• Use freshly prepared, equilibrated reagents at working temperature to minimize baseline drift.
• For plate-based formats, use flat-bottom, clear plates and measure absorbance with pathlength corrections as appropriate.
• For kinetic measurements, ensure linearity with respect to time and enzyme concentration.

Quality and Grades

• Grade: BioReagent (per Product Data). This denotes suitability for biological/biochemical research, typically implying control of contaminants that could interfere with enzymatic assays (e.g., heavy metals, microbial load, or reactive impurities). Exact specifications for this item are Not specified; refer to CoA/Spec Sheet.

What BioReagent grade means (general)

• Function-focused QC: Emphasis on performance in biological systems (e.g., consistent color development, low background).
• Low interfering substances: Minimized levels of reducing agents, phosphate, or chelators where such species could disrupt coupled reactions (general expectation; see CoA for details).

Kit-specific considerations

• Inter-component compatibility: Buffers, substrates, and enzymes are formulated to function together for robust colorimetric signal generation.
• Documentation: For lot-specific acceptance criteria (e.g., signal-to-blank ratio, linearity with enzyme amount), consult the CoA and the instruction booklet. If UV cutoff, residual phosphate, or metal limits are important to your workflow, verify in the CoA—Not specified for this item.

Best practices

• Perform a standard curve and include positive/negative controls with each run to document performance against your internal QC requirements.
• Record lot numbers and retain CoA/SDS for traceability in regulated labs (GLP/GMP settings may require additional qualification steps).

Reaction and Applications

Intended use: quantitative or semi-quantitative measurement of starch phosphorylase activity in biological extracts or purified enzyme using a colorimetric readout.

Application scope (literature/general)

• Sample types: Plant tissues (leaves, seeds), microbial lysates, and purified phosphorylase isoforms, following appropriate extraction methods that preserve activity and remove interfering phosphate or reducing sugars.
• Assay principles:
  • Monitor conversion of α-1,4-glucans in the presence of inorganic phosphate to glucose-1-phosphate (G1P), with color development through a coupled detection system.
  • Readout at a visible wavelength using a plate reader or spectrophotometer.
• Use cases:
  • Enzyme characterization (Km, Vmax) via initial-rate kinetics.
  • Comparative activity profiling across tissues, developmental stages, or genetic backgrounds.
  • Process monitoring in enzyme production or purification.

Practical tips (general)

• Pre-clear samples to remove free phosphate when the detection chemistry is phosphate-based; desalting columns or spin filters are commonly used.
• Keep reactions in the linear range by titrating enzyme amount and time; verify linearity with time-course plots.
• Include blanks (no enzyme) and negative controls (no substrate or no phosphate) to correct background.
• Maintain constant temperature and mix thoroughly to ensure reproducibility.

Kit-specific details such as chromophore identity, wavelength, and standard curve components are Not specified for this item; consult the booklet.

Reaction Conditions

Typical conditions for starch phosphorylase colorimetric assays (literature/general; adapt to your enzyme source):

• Temperature: 25–37°C; maintain ±0.5°C for kinetic reproducibility.
• pH: Near neutral, commonly 6.8–7.4, buffered at 10–100 mM (HEPES, MOPS, Tris, or phosphate). Optimize per isoform.
• Substrate: Soluble starch or malto-oligosaccharides at concentrations that ensure initial-rate conditions; prewarm to assay temperature.
• Cofactors/ions: As required by any coupling enzymes (e.g., Mg2+ for phosphoglucomutase/G6PDH systems, literature-dependent).
• Detection: Colorimetric read at a visible wavelength (e.g., 570 ± 20 nm or 620–660 nm depending on dye chemistry). Exact λmax for this item is Not specified; refer to the booklet.
• Timing: Measure initial rates over 5–20 min ensuring linearity. End-point formats may incubate 20–60 min before quench/read.

Example workflow (literature template)

1. Prepare a standard curve (e.g., glucose-1-phosphate or inorganic phosphate, depending on the coupling chemistry).
2. Assemble reaction mix (buffer, substrate, phosphate, coupling reagents) and equilibrate.
3. Initiate with enzyme-containing sample; mix quickly and start timing.
4. Monitor absorbance kinetically or incubate to end-point and read.
5. Subtract blanks, convert absorbance to concentration using the standard curve, and calculate activity in Units/mL (1 U = 1 µmol product min⁻¹).

Kit-specific concentrations, volumes, and timing are Not specified; follow the provided manual.

Safety and Handling

Follow standard laboratory precautions for handling biochemical assay reagents. Component-specific hazards (acids, detergents, dyes, or preservatives) may apply.

Item-specific hazard data

• Signal word / H-statements / GHS classification / pictograms: Not specified for this item; refer to the SDS for each component.

General safety guidance (not a substitute for SDS)

• PPE: Lab coat, safety glasses, and suitable gloves (e.g., nitrile). Handle powders and lyophilized enzymes with care to avoid inhalation.
• Engineering controls: Work in a well-ventilated area; avoid aerosol generation. For volatile or irritating components, use a fume hood.
• Incompatibilities: Avoid strong oxidizers and strong acids/bases unless specified by the protocol. Do not mix with bleach-containing solutions if reagents include amines or thiols.
• Peroxide formation: Not applicable to aqueous kit buffers; organic solvent use should follow standard peroxide testing if applicable (not typical for this kit).
• First aid (overview): In case of skin/eye contact, rinse with water for at least 15 minutes. If inhaled, move to fresh air. If ingested, rinse mouth with water. Seek medical attention as needed. Defer to SDS for authoritative instructions.
• Waste: Dispose of color-developing solutions and enzyme-containing waste per institutional guidelines for chemical/biological waste. Avoid drain disposal unless permitted by local regulations.

Always consult the product’s SDS and the kit booklet for component-specific hazards before use.

Solvent Selection

This is an aqueous, colorimetric enzyme assay kit; organic solvent selection is generally not applicable.

• Primary medium: Water-based buffers supplied with or specified by the kit (general). Maintain ionic strength and pH as directed.
• Organic cosolvents: Typically avoided because they may inhibit enzyme activity or alter colorimetric responses. If sample matrices contain organic solvents, keep final concentration low (literature practice: ≤1–5% v/v) and verify no impact using spiked controls.
• Detergents/surfactants: If the kit tolerates mild nonionic detergents (e.g., Tween-20) to reduce nonspecific interactions, follow the kit manual; otherwise avoid.

Comparison (general guidance)

• Aqueous buffers provide native-like conditions and stable chromogenic response.
• Aqueous-organic mixtures may aid in solubilizing hydrophobic samples but risk assay inhibition; validate empirically.

For this item, the exact buffer composition and tolerances to additives/solvents are Not specified; refer to the instruction booklet/CoA.

Storage and Reconstitution

• Storage conditions (as supplied): Store at 2–8°C (per Product Data). Keep tightly closed and protect from light if color reagents are included.
• Shipping: Shipped on wet ice (per Product Data). Inspect immediately; if any components are frozen or warmed, follow the kit’s manual for suitability.

Component-specific guidance

• Exact storage requirements for individual components (e.g., enzymes, buffers, standards) and any reconstitution instructions are Not specified for this item; refer to the instruction booklet/CoA.

General best practices (kit handling)

• On receipt, inventory all components and segregate by storage requirement if indicated by the booklet.
• Before use, allow refrigerated components to equilibrate to room temperature (or assay temperature) to avoid condensation and ensure accurate pipetting.
• Mix reconstituted reagents gently to avoid foaming; use calibrated pipettes.
• Avoid repeated freeze–thaw of enzyme-containing solutions; prepare single-use aliquots if the manual recommends freezing.
• Protect chromogenic reagents from light and air exposure; cap promptly after use.

Stability

• Shelf-life, post-reconstitution stability, and allowable storage excursions are Not specified for this item; consult the CoA/Spec Sheet and the kit booklet.

Always adhere to the kit’s specific storage and reconstitution instructions to ensure performance.

Structure and Identity

This product is a multi-component enzymatic assay kit intended to quantify starch phosphorylase activity by a colorimetric readout.

• Product type: Enzymatic activity assay kit (colorimetric)
• Analyte measured: Starch phosphorylase activity (EC 2.4.1.1) — catalyzes phosphorolysis of α-1,4-glucans to yield glucose-1-phosphate (G1P) (literature/general)
• Format: Reagents supplied for end-point or kinetic absorbance measurement in cuvette or microplate (general kit description)

Item-specific identifiers

• SKU: S1522137
• Grade/Purity: BioReagent (per Product Data)
• Molecular formula / weight / SMILES / InChIKey: Not applicable to a kit; Not specified for this item; refer to CoA/Spec Sheet.

Structural features (assay principle, literature/general)

• Assays for starch phosphorylase typically use a coupled-enzyme system that converts the primary product (G1P) to a chromophore-forming species measurable at visible wavelengths.
• Common coupling routes (literature examples):
  • G1P → G6P (phosphoglucomutase) → NADPH formation (G6PDH) with downstream color-development reagents; or
  • Detection of released inorganic phosphate via molybdate/malachite green; or
  • Detection of reducing sugars via chromogenic reagents.
• The exact coupling chemistry and chromophore in this kit are Not specified for this item; refer to the kit booklet/CoA.

Synthetic Utility

Not typically applicable. This product is an enzymatic activity assay kit rather than a synthetic reagent or building block.

Context for chemists (general)

• While starch phosphorylase can be used in chemoenzymatic synthesis to generate glucose-1-phosphate or elongate α-1,4-glucans in the reverse direction under controlled conditions, this kit is formulated for activity measurement, not for preparative synthesis.
• Reagent volumes, stabilizers, and color-developing chemistries in assay kits are optimized for analytical performance, not scalability.

If enzymatic synthesis is your goal, source purified enzyme preparations and process-compatible buffers; do not repurpose analytical kits for production chemistry.

Target Specificity

This product is not an antibody or affinity reagent; classic target-specific parameters (antigen, clone, isotype, species reactivity) do not apply.

Assay target (general)

• Measures activity attributable to starch (α-glucan) phosphorylase in the sample matrix. Isoform and species specificity depend on sample preparation and assay conditions rather than antibody recognition.

Any claims of isoform selectivity or species restriction are Not specified for this item; refer to the booklet if available.