DSPE-PEG-Fluor 647,MW 2000 , CAS No.D1450427

CAS: D1450427 Cat. No.: D1450427 Peso molecolare: 2000(Average)

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Panoramica

DSPE-PEG-Fluor 647, MW 2000 is a fluorescent lipid (Ex/Em=648/671 nm) composed of PEG-lipid-dye conjugation. DSPE is a phospholipid. Fluor 647 is a fluorescent dye that can be used for microscopy in vivo.

Specifications

Condizioni di conservazione di stoccaggio

Store at -20°C

Spedito in

Ice chest + Ice pads

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Nomi e identificatori

Peso molecolare

2000(Average)

Application Protocols

General workflows for incorporating DSPE‑PEG‑Fluor 647 into lipid systems (optimize for your formulation and instrumentation):

• A. Thin‑film hydration (co‑formulation)

  1. Dissolve bulk lipids and DSPE‑PEG‑Fluor 647 in chloroform:methanol (9:1 v/v). Total dye content commonly 0.1–1 mol% of total lipid (literature guidance).
  2. Evaporate solvent under rotary evaporation to form a uniform film; dry under high vacuum ≥2 h to remove residuals.
  3. Hydrate with PBS or HEPES buffer pre‑warmed to 60 °C. Vortex and briefly sonicate until suspended.
  4. Extrude through 200 nm then 100 nm membranes at temperature. Protect from light throughout.
  5. Purify by SEC (e.g., Sepharose CL‑4B) in buffer to remove free dye.

• B. Post‑insertion into pre‑formed vesicles

  1. Warm vesicle suspension above DSPE Tm (∼60 °C).
  2. Add a minimal DMSO stock of DSPE‑PEG‑Fluor 647 dropwise to achieve desired mol% while keeping DMSO ≤1–2% v/v final.
  3. Incubate 30 min with gentle mixing; cool to room temperature; purify by SEC.

• C. Fluorescence measurement

  • Excite with 633–647 nm; collect emission 660–720 nm (literature). Include unlabeled controls for background subtraction.

• Notes:

  • Exact concentrations, times, and temperatures for this item are not specified; adjust empirically based on vesicle composition and size.

Biological Roles

This reagent has no endogenous biological role; it is a synthetic probe designed to report on lipid assembly behavior and to enable optical detection.

• Functional concept (general):

  • The DSPE anchor embeds stably in phospholipid bilayers, exploiting hydrophobic interactions of its two C18 chains. The PEG spacer confers hydration and steric stabilization, projecting the far‑red Fluor 647 dye into the aqueous phase, reducing self‑quenching and nonspecific interactions.
  • Far‑red excitation/emission reduces background from cellular autofluorescence and enables deeper optical penetration in thick samples.

• Typical experimental contexts:

  • Tracking vesicle–cell interactions (binding, internalization) via confocal or flow cytometry.
  • Monitoring liposome integrity, fusion, and cargo release in biochemical assays.
  • Mapping membrane microdomains or curvature preferences when combined with other labeled lipids.
  • Studying nanoparticle protein corona formation and opsonization using fluorescence readouts.

• Biocompatibility considerations (general, non‑clinical):

  • PEG chains can reduce nonspecific protein binding and aggregation; however, the appended dye introduces aromaticity and charge that may alter interactions. Optimize labeling density to balance signal with minimal perturbation.
  • Validate that the probe does not affect the specific biological readout (e.g., receptor binding or membrane mechanics) by including unlabeled controls.

• Note: All uses are for research and laboratory investigations only; not for diagnostic or therapeutic use.

Buffer Applications

Buffers support hydration, dispersion, and purification of DSPE‑PEG‑Fluor 647–containing assemblies.

• Hydration buffers (general guidance):

  • Phosphate‑buffered saline (PBS) or HEPES‑buffered saline (HBS), pH 7.2–7.5 (literature), commonly used for liposome formation. Warm to 55–65 °C during hydration to accommodate DSPE transitions.
  • For sensitive cargo, use appropriate osmolarity and ionic strength; include sugars (e.g., 5–10% sucrose or trehalose) for cryo/lyoprotection when needed.

• Detergent‑assisted incorporation (if direct hydration is challenging):

  • Non‑ionic detergents (e.g., mild alkyl polyglucosides or polysorbates) can solubilize mixed micelles; after equilibration, remove detergent by dialysis, Bio‑Beads, or SEC to reconstitute bilayers with the dye‑PEG displayed.

• Purification and cleanup:

  • Size‑exclusion chromatography in PBS/HBS efficiently removes non‑incorporated dye and small aggregates; monitor by far‑red fluorescence.
  • Dialysis (MWCO 50–100 kDa for liposomes) against large buffer volumes can also clear free dye; exchange to final buffer simultaneously.

• Compatibility notes:

  • Avoid buffers with primary amines or high concentrations of reducing agents that could interact with certain dye chemistries (general caution); verify for your variant.
  • Maintain pH near neutral to preserve dye brightness and lipid integrity (literature). Exact pH stability ranges for this item are not specified.

Green Alternatives

While the conjugate itself is fixed, formulation and handling can be made greener by solvent choices and process design.

• Greener solvent substitutions (general guidance):

  • Replace chloroform/DCM films with ethanol or isopropanol when feasible; many lipid formulations can be prepared from concentrated ethanol stocks followed by aqueous dilution and solvent removal.
  • Prefer supercritical CO2–assisted or microfluidic ethanol injection methods for scalable, lower‑toxicity nanoparticle assembly.

• Comparison (general, non‑specification):

  | Step | Conventional option | Greener alternative | Trade‑offs | |---|---|---|---| | Lipid dissolution | Chloroform, DCM | Ethanol, isopropanol | Slightly reduced solubility for some lipids; may need higher temp; azeotrope removal simpler and safer | | Stock solutions | DMF/DMSO | Glycerol carbonate, PEG‑400, ethanol | Viscosity or miscibility changes; effect on bilayer insertion must be tested | | Particle formation | Thin‑film hydration | Ethanol injection or microfluidics | Equipment needed; good for scale and reproducibility |

• Operational best practices:

  • Minimize solvent volumes; recover solvents via rotavap/solvent recycling.
  • Use amber, reusable glassware to reduce consumables; protect from light to extend reagent lifespan and reduce waste.

Pharmaceutical Uses

This material is provided for research use only and is not an approved excipient for clinical applications. Nonetheless, it is commonly used in pre‑formulation and process development studies as a tracer or model component.

• Typical roles in non‑clinical development workflows (general):

  • Fluorescent tracer in liposome/LNP process optimization (e.g., ethanol injection, microfluidics, thin‑film hydration) to quantify encapsulation, recovery, and stability during scale‑up.
  • Aid for in vitro imaging of nanoparticle–cell interactions to guide selection of PEG content and surface presentation.
  • Tool for QC method development (fluorescence‑based SEC/HPLC to monitor free dye vs. particle‑associated dye).

• Documentation:

  • No pharmacopeial monograph is implied for this conjugate. Batch‑specific CoA should be consulted for analytical identity and purity.

• Practical considerations:

  • Keep fluorescent label fraction low to minimize perturbation of particle pharmacotechnical properties during research studies.
  • Validate that residual organic solvent is within acceptable internal limits after processing; choose greener solvent systems where possible.

• Compliance note:

  • Not for human or veterinary use, not for diagnostic procedures. Results from research‑grade materials should be re‑qualified with GMP‑grade analogs if transitioning toward regulated studies.

Physical Properties

• Item-specific specifications: Boiling point, melting/phase transition, density, refractive index, UV–vis maxima, extinction coefficient, logP, pKa, and water content: Not specified for this item; refer to CoA/Spec Sheet.

• Literature/general expectations for DSPE‑PEG‑far‑red dyes (non‑specification):

  • Physical form: typically a dark‑colored solid/film or lyophilized powder; strongly light‑sensitive.
  • Amphiphilicity: DSPE anchor is highly hydrophobic; PEG and dye increase aqueous compatibility once assembled into micelles or bilayers.
  • Solubility behavior: often dissolvable in organic solvents used for lipids (e.g., chloroform, dichloromethane, methanol) and in DMSO/DMF; dispersible in aqueous buffers upon film hydration above lipid transition temperatures or with mild detergents. Exact solubilities for this item are not specified.
  • Thermal transitions: DSPE has a high gel–fluid transition temperature (Tm ~55 °C, literature for DSPE). PEGylation can lower effective mixing barriers, but the underlying DSPE Tm often necessitates warming for hydration and insertion into bilayers. Item‑specific Tm not specified.
  • Spectral properties (literature, dye family): Fluor 647‑type fluorophores commonly show excitation ~640–650 nm and emission ~665–670 nm with high photostability and low background in biological samples. Exact λmax/ε for this item are not specified; verify on CoA.

• Practical notes:

  • Protect from light and moisture. Use amber glassware and minimize air/light exposure during film preparation and reconstitution.

Quality and Grades

• Item-specific quality attributes provided: Grade/purity not specified for this item; refer to CoA/Spec Sheet.

• Practical interpretation for PEG–lipid–dye conjugates:

  • Average molecular weight (per product title): ~2000 Da PEG spacer. For PEGylated materials, suppliers typically report an average MW distribution (polydispersity inherent to PEG). Batch‑specific Mn/Mw or dye substitution ratios may be provided on the CoA.
  • Purity considerations: Analytical confirmation commonly includes HPLC/UPLC profiles and UV–vis spectra to confirm dye identity and to estimate dye loading. Absence of such metrics here means users should verify on receipt (e.g., analytical RP‑HPLC, MALDI/ESI‑MS as applicable).
  • Stabilizers/additives: Not specified for this item. Many fluorescent lipids are shipped without stabilizers; verify CoA if antioxidants or counterions are present.

• What “research use only” implies:

  • Material is intended solely for laboratory research and method development. Not intended for human or veterinary use, diagnostics, or clinical applications.

• Recommended user QC (guidance):

  • Record UV–vis spectrum to verify far‑red absorbance profile; assess integrity post‑reconstitution.
  • If used for quantitative labeling, determine working concentration by absorbance using dye family’s ε (literature) and confirm incorporation into lipid assemblies by fluorescence or chromatography.

Reaction and Applications

This product is primarily an analytical/probing reagent rather than a synthetic reactant. Its core utility is in labeling and tracking lipid assemblies and membranes.

• Typical research applications (general/literature):

  • Fluorescent labeling of liposomes, lipid nanoparticles (LNPs), and micelles for visualization, trafficking studies, and recovery measurements.
  • Preparation of PEGylated, far‑red fluorescent vesicles for confocal microscopy, flow cytometry of vesicle–cell interactions, and in vitro permeability assays.
  • FRET/FLIM experiments when paired with appropriate donors/acceptors; far‑red emission minimizes autofluorescence.
  • Quantification of vesicle concentration and integrity by fluorescence readouts in release/rupture assays.
  • Surface presentation of PEG‑dye to track nanoparticle protein corona formation and colloidal stability.

• Incorporation strategies:

  • Co‑formulation: dissolve with bulk lipids in organic solvent, make a thin film, dry thoroughly, then hydrate above DSPE Tm with buffer; extrude to size. Typical mole fractions for tracer labeling are low (e.g., 0.1–1 mol% of total lipid; literature guidance—optimize empirically for your system).
  • Post‑insertion: add a small DMSO or ethanol stock to pre‑formed vesicles warmed above Tm and incubate to allow PEG‑dye insertion; remove free dye by SEC or dialysis.

• Practical considerations:

  • Excessive labeling can perturb bilayer packing and protein interactions—titrate to the minimal effective load.
  • Validate spectral settings (laser ~633–647 nm; emission collection ~660–720 nm; literature) to avoid bleed‑through and maximize S/N.

Reaction Conditions

Classical organic reaction conditions are not the focus for this material. Instead, consider formulation/assembly conditions for effective use.

• Film hydration and extrusion (general literature guidance):

  • Dissolve lipids and DSPE‑PEG‑Fluor 647 in chloroform:methanol, form a thin film, dry thoroughly under vacuum. Hydrate with warm buffer (55–65 °C) while vortexing/sonicating. Extrude through polycarbonate membranes (e.g., 100–200 nm) at temperature to achieve monodisperse vesicles. Remove free dye by SEC.

• Ethanol (or isopropanol) injection:

  • Prepare a concentrated ethanol solution of lipids plus DSPE‑PEG‑dye. Inject into stirred/warmed aqueous buffer at controlled flow/ratio to nucleate nanoparticles. Dialyze or diafilter to reduce solvent content and remove unincorporated dye.

• Post‑insertion into pre‑formed vesicles:

  • Add a minimal volume of DMSO or ethanol stock of the probe to warmed vesicles (above DSPE Tm). Incubate 15–60 min with gentle mixing; then purify via SEC. Optimize temperature and time empirically to balance insertion efficiency and vesicle integrity.

• Spectroscopic settings (literature, dye family):

  • Excitation with 633–647 nm lasers; collect emission ~660–720 nm. Calibrate detectors to avoid saturation; validate linearity for quantitation.

• Yields/outcomes:

  • Quantitative “yields” are defined as incorporation efficiency and fluorescence recovery; values are system‑dependent and should be determined experimentally for each formulation.

Safety and Handling

• GHS/SDS data for this specific item:

  • Signal word, hazard statements, pictograms, and classification: Not specified for this item; refer to SDS.

• General laboratory precautions (non‑clinical research use only):

  • Wear appropriate PPE: lab coat, nitrile gloves, safety glasses. Handle powders and films in a clean, low‑dust environment; avoid aerosolization.
  • Light sensitivity: protect from ambient and UV light to prevent dye photobleaching and potential degradation.
  • Thermal handling: DSPE‑containing materials often require warming (40–70 °C) for dissolution/film hydration. Use heat‑resistant gloves and avoid overheating.
  • Incompatibilities (general): strong oxidizers and strong acids/bases may degrade the organic dye and lipid chains; avoid reactive nucleophiles/electrophiles that could attack linkages.
  • Ventilation: handle organic solvents (e.g., chloroform, DCM, methanol) in a fume hood. Avoid inhalation/ingestion of dust or vapors from co‑solvents.

• First‑aid overview (defer to SDS for specifics):

  • Skin/eye contact: rinse with water for several minutes; remove contaminated clothing. Seek medical attention if irritation persists.
  • Inhalation of solvent vapors: move to fresh air; obtain medical advice if symptoms occur.
  • Ingestion: rinse mouth; do not induce vomiting; seek medical attention.

• Waste: collect dye‑containing organic/aqueous waste separately; dispose according to institutional and regulatory guidelines for organic dyes and halogenated/non‑halogenated solvent waste.

Solvent Selection

This amphiphilic conjugate behaves as a lipid in organic media and as a PEGylated probe in aqueous systems when incorporated into assemblies.

• Primary solvent choices (general guidance):

  • Lipid film preparation: chloroform or chloroform:methanol (2–1 to 9–1, v/v) enable homogeneous dissolution with other phospholipids/cholesterol. Dry thoroughly to remove residual solvents.
  • Polar aprotic solvents: DMSO or DMF can solubilize the conjugate for stock solutions; subsequent dilution into buffer with detergents or into pre‑formed liposomes is common.
  • Aqueous buffers: direct dissolution is limited; dispersion improves above DSPE Tm with sonication or with non‑ionic detergents (e.g., Tween‑20, Triton X‑100 alternatives) followed by detergent removal if needed.

• Polarity/miscibility profile (qualitative):

  • Hydrophobic tails favor nonpolar/halogenated organic solvents; PEG/dye end imparts some polarity, aiding DMSO solubility. In water, stable incorporation typically requires micelles, vesicles, or protein/lipid carriers.

• Choosing among alternatives:

  • For thin‑film hydration and liposome co‑formulation: chloroform:methanol is conventional and gives uniform films; alternatively, isopropanol/ethanol can work for greener workflows (see Green Alternatives).
  • For rapid screening or bioconjugation into pre‑formed bilayers: DMSO micro‑aliquots (<1–2% v/v final) minimize bilayer disruption.

• Practical tips:

  • Warm solutions (40–60 °C) and use brief bath sonication to aid dissolution and insertion into membranes.
  • Always protect solutions from light; use amber vials and purge headspace with inert gas to limit oxidation.

Storage and Reconstitution

• Item-specific storage and shipping (from Product Data):

  • Storage: Store at −20 °C.
  • Shipping: Ice chest + ice pads.

• General handling:

  • Protect from light at all times; store in amber vials. Allow container to equilibrate to room temperature in the dark before opening to prevent moisture condensation.
  • If supplied as a film or powder, keep desiccated. Reseal under inert gas if possible after use.

• Reconstitution (general guidance; item‑specific solvents not specified):

  • For organic stocks: dissolve in chloroform or chloroform:methanol for film preparation; or dissolve in anhydrous DMSO/DMF to make concentrated stocks (e.g., 1–10 mM based on nominal dye content; determine empirically using absorbance). Filter through 0.22 μm PTFE if needed.
  • For direct aqueous use: hydrate mixed lipid films with warm buffer (55–65 °C) and sonicate or extrude. Alternatively, add small DMSO/ethanol aliquots of the probe to warmed vesicles for post‑insertion. Remove free dye by SEC/dialysis.

• Stability:

  • Avoid repeated freeze–thaw cycles; aliquot upon first receipt. Keep frozen, dry, and protected from light for long‑term storage. Working solutions in organic solvents are best stored at ≤−20 °C and used promptly; aqueous formulations should be used within days and stored at 2–8 °C in the dark.

• Research use note: For research use only.

Structure and Identity

Amphiphilic fluorescent PEG–lipid for labeling lipid assemblies and biomembranes.

• Item-specific facts (from Product Data):

  • Product name: DSPE-PEG-Fluor 647, MW 2000 (SKU: D1450427)
  • Nominal average molecular weight: ~2000 Da (from product title; typical for PEGylated conjugates; exact distribution not specified)
  • CAS, SMILES, InChIKey, molecular formula: Not specified for this item; refer to CoA/Spec Sheet.

• Structural description (general/literature):

  • Composed of a phospholipid anchor, DSPE (1,2‑distearoyl‑sn‑glycero‑3‑phosphoethanolamine; C18:0/C18:0), covalently linked via a poly(ethylene glycol) (PEG) spacer (~2 kDa) to a far‑red fluorophore in the “Fluor 647” family (spectrally similar to cyanine/Alexa Fluor 647‑type dyes).
  • Key functional groups: long‑chain aliphatic tails (hydrophobic), glycerophosphoethanolamine headgroup (ionic), PEG chain (hydrophilic, flexible), and an aromatic polymethine‑type chromophore (delocalized cationic/aromatic system) at the distal end.
  • Architecture: AB amphiphile. The DSPE moiety embeds in lipid bilayers; the PEG projects into the aqueous phase, presenting the 647 fluorophore.
  • Stereochemistry: DSPE is typically sn‑configured at glycerol; dye portion contains conjugated double bonds (E/Z configuration patterns depend on dye variant; item‑specific stereochemistry not specified).

• 2D structure in words (general): two parallel C18 alkyl chains attached to a glycerol backbone bearing a phosphate–ethanolamine linker; the ethanolamine nitrogen is PEGylated, and the PEG terminus bears a far‑red dye core.

Synthetic Utility

This conjugate is not typically employed as a building block for chemical synthesis; it is a finished probe designed for physical incorporation into lipid assemblies.

• Limited synthetic roles (general):

  • Can serve as a modular amphiphile in supramolecular assembly studies, where the PEG–dye serves as a reporter of assembly/disassembly rather than a reactive handle.
  • If supplied with latent functionalities (not specified for this item), PEG termini can sometimes be used for further bioconjugation (e.g., NHS/azide/alkyne end groups). No such functionality is specified here—refer to CoA.

• Retrosynthetic perspective:

  • The molecule comprises three domains—lipid (DSPE), spacer (PEG ~2 kDa), and dye (Fluor 647 family). In synthetic routes, these are often joined via amide or carbamate linkages, but end‑user laboratories typically do not modify this structure.

• Bottom line:

  • Consider this reagent as a specialized labeling component to be blended into formulations rather than a substrate for chemical transformations.

Target Specificity

Not an affinity reagent (no antigen/clone/isotype). Target binding specificity is not applicable.

• Spectral specificity (literature, dye family):

  • Fluor 647‑type dyes are excited efficiently near 640–650 nm and emit near 665–670 nm, allowing selective detection in the far‑red channel with minimal cellular autofluorescence.
  • Compatible filter sets typically include excitation 620–650 nm and emission 660–720 nm. Exact spectral maxima and bandwidths for this item are not specified; verify empirically.

• Functional “specificity” in use:

  • Bilayer specificity arises from the DSPE anchor embedding in lipid membranes; the PEG spacer projects the dye into the aqueous phase, reducing nonspecific surface interactions compared to non‑PEGylated dyes.