DSPE-PEG-Cy5, MW 5000 , CAS No.D1439604

CAS: D1439604 Cat. No.: D1439604 Peso molecolare: 5000(Average)

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Panoramica

DSPE-PEG-Cy5, MW 5000 is a PEG phospholipid with Cy5 dye used in protein/nucelic acid labeling and fluorescence microscopy. The polymer can self-assemble in aqueous solution to form micelles/lipid bilayer and used to prepare liposomes or nanoparticles for nutrients delivery such as mRNA or DNA vaccine.

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: 5000(Average)

Application Protocols

General, literature-based protocol for preparing Cy5-labeled liposomes (example: 1 mol% DSPE-PEG-Cy5):

• Materials

  • Phospholipid matrix (e.g., DSPC or egg PC), cholesterol, DSPE-PEG-Cy5.
  • Solvents: CHCl3:MeOH (9:1) or ethanol; buffer: HEPES 10 mM, NaCl 150 mM, pH 7.4.

• Procedure (thin-film hydration/extrusion)

  1. Dissolve lipids in organic solvent at desired molar ratios (e.g., 55% phospholipid, 44% cholesterol, 1% DSPE-PEG-Cy5). Transfer to a round-bottom flask protected from light.
  2. Evaporate solvent under reduced pressure to a uniform film; dry under high vacuum ≥2 h.
  3. Hydrate with prewarmed buffer (≥65–70 °C for DSPE-containing systems) to 10 mM total lipid; vortex to detach film. Optional brief bath sonication.
  4. Extrude 11× through 200 nm then 100 nm polycarbonate membranes at temperature above Tm.
  5. Remove dust/aggregates by 0.22 μm filtration. Store at 2–8 °C protected from light and use promptly.

• Fluorescence measurement (literature)

  • Excite at 646–650 nm; collect emission 660–700 nm. Prepare solvent-matched blanks. To estimate dye incorporation, compare fluorescence before/after addition of detergent (e.g., Triton X-100) to relieve self-quenching.

• Notes

  • Keep dye mol% low to minimize self-quenching and membrane perturbation. Validate absence of free dye using SEC or dialysis before quantitative studies.

For microfluidic ethanol injection, substitute anhydrous ethanol as solvent and remove ethanol post-assembly by dialysis/diafiltration.

Biological Roles

This product is a synthetic probe; it does not have an intrinsic biological role. The following notes describe how it interfaces with biological systems in research settings (literature/general):

• Membrane incorporation: The DSPE anchor embeds in phospholipid bilayers with high affinity due to two saturated C18 chains; the PEG spacer extends into the aqueous phase, reducing nonspecific protein adsorption and prolonging colloidal stability of vesicles in complex media.
• Fluorescent reporting: Cy5 (far-red) minimizes autofluorescence from cells and tissues compared with shorter-wavelength dyes, enabling high signal-to-background in microscopy and flow-based detection of labeled vesicles or supported bilayers.
• Stealth characteristics: PEG chains generate a hydration shell that can hinder opsonization in biological fluids (general phenomenon of PEGylation). In cell-free assays, this reduces surface fouling and aggregation.
• Energy transfer: In mixed-dye systems (e.g., Cy3/Cy5), DSPE-PEG-Cy5 can serve as an acceptor in FRET studies of membrane mixing, lipid diffusion, and domain formation. PEG spacing helps reduce dye–dye self-quenching at low mol%.
• Environmental sensitivity: Cy5 fluorescence can be affected by local polarity, aggregation state, and oxygen concentration. Encapsulation within membranes can slightly shift spectra and alter quantum yield; calibrate in the intended medium.

All uses are for research and laboratory investigations only; no biological activity or therapeutic effects are claimed or implied.

Buffer Applications

This item is not a buffer reagent, but buffers are critical for formulating DSPE-PEG-Cy5 into liposomes and related assemblies. General, literature-based guidance:

• Common hydration buffers

  • HEPES-buffered saline (HBS; 10–20 mM HEPES, 150 mM NaCl, pH 7.4) for general liposome work.
  • PBS (1×, pH 7.2–7.4) for routine dispersion and handling; note potential phosphate interactions with divalent cations.
  • Citrate or acetate buffers (pH 4–6) are used in ionizable-lipid LNP assembly workflows; the dye-lipid co-assembles but optical properties may shift with pH/ionic strength.

• Practical tips

  • Warm buffers to ≥60–70 °C when hydrating DSPE-rich films to surpass the DSPE Tm and promote uniform incorporation.
  • Filter (0.22 μm) and degas buffers to reduce particulates and bubble formation during extrusion.
  • Include 5–10% glycerol or 5–20% sucrose when preparing samples for freeze–thaw cycling or lyophilization studies to protect vesicle integrity; verify effects on fluorescence.

• Detergent-assisted incorporation

  • Nonionic detergents (e.g., octyl glucoside) can solubilize lipids; after mixing, remove detergent by dialysis or Bio-Beads to reconstitute labeled membranes.

Note: Ionic strength and pH can modulate Cy5 photophysics and self-association; maintain consistent buffer composition across experiments and collect appropriate blanks.

Green Alternatives

Greener handling focuses on solvent and process choices rather than changing the amphiphile, since the functional need is a DSPE-PEG-anchored Cy5.

• Solvent substitutions (literature-informed)

  • Replace chloroform/DCM with ethanol or isopropanol for lipid dissolution when feasible (microfluidic ethanol injection is well established). Tradeoff: Some DSPE-PEG-dye conjugates dissolve more slowly in alcohols; warming and filtration may be required.
  • Use 2-MeTHF in place of DCM for certain casting workflows. Tradeoff: Slightly higher boiling point and different evaporation kinetics; confirm complete removal to avoid membrane perturbation.

• Process intensification

  • Employ closed, recoverable-solvent rotary evaporation with cold traps to reduce emissions.
  • Prefer microfluidic or in-line mixing in aqueous ethanol over bulk solvent casting, minimizing chlorinated solvent use.

• Material-level alternatives

  • If spectral flexibility exists, consider dyes excitable by common 488/561 nm lasers (e.g., BODIPY, rhodamine) that may offer higher photostability in some systems; however, this changes optical channels and is not a drop-in replacement.

Comparison table (general):

• Chloroform/DCM: Excellent solubility; high toxicity; ozone/hazard concerns.
• Ethanol: Safer, renewable; may need higher temperature and longer drying.
• 2-MeTHF: Bio-based option; good solvency vs DCM; distinct odor and peroxidation risk over long storage—monitor inhibitors.

Note: Verify membrane properties and dye performance after any solvent/process change.

Pharmaceutical Uses

No therapeutic or clinical claims are made. In a research and development/formulation context, DSPE-PEG-Cy5 can serve the following roles (general literature):

• Process tracer and analytical marker

  • Inclusion at trace levels in research-grade liposomes and lipid nanoparticles (LNPs) to monitor assembly efficiency, size-fractionation recovery, and stability via fluorescence without altering the primary payload.

• Visualization in device/process development

  • Enables real-time fluorescence-based optimization of microfluidic mixers, extrusion membranes, and chromatography steps during formulation development.

• Excipient analog assessment

  • PEGylated DSPE lipids are widely used excipients in research formulations; the Cy5 label provides a handle for distribution and surface coverage studies on supports and delivery devices.

• Method development and QC

  • Can be used to develop HPLC/SEC detection methods (fluorescence channels near 650/670 nm) for tracking lipid-associated fractions versus free dye during purification.

Regulatory/compendial status: Not specified for this item; refer to CoA/Spec Sheet. Any use is for non-clinical, laboratory research only. For translational work, unlabeled excipients or GMP-grade materials are typically required; fluorescent analogs are generally limited to development and in vitro characterization.

Physical Properties

Item-specific numerical specifications (mp/bp, density, etc.): Not specified for this item; refer to CoA/Spec Sheet.

General/literature characteristics for DSPE-PEG-dye conjugates (informational):

• Physical state/appearance: Typically a dark blue/purple solid or waxy material (color from Cy5); PEGylated lipids are often glassy or semi-solid at room temperature.
• Solubility profile (literature):
  • Good solubility in chloroform, dichloromethane, and mixtures of chloroform:methanol commonly used for lipid film preparation.
  • Soluble in anhydrous DMSO and DMF; can be dispersed in aqueous buffers when incorporated into micelles/bilayers or co-formulated with helper lipids and warmed above DSPE transition temperature.
  • Practically insoluble in non-polar alkanes; limited direct solubility in water without assembly.
• Amphiphilicity: Strong; DSPE anchors into bilayers, PEG chain is hydrated, Cy5 is solvatochromic to some extent.
• Thermal behavior (literature): DSPE main-chain gel–liquid crystalline transition Tm ~74 °C; incorporation of PEG and Cy5 perturbs/lowers the cooperative transition of mixtures. Handle above ~60–70 °C during hydration/extrusion for uniform films when DSPE is a major component.
• Optical properties (Cy5; literature):
  • Absorption λmax ~646–650 nm; emission λmax ~662–670 nm (environment-dependent); ε ~2.5–2.6×10^5 M−1 cm−1 reported for Cy5 dyes in organic media.
  • Strongly light-sensitive; photobleaches upon prolonged illumination and in presence of oxygen.
• Partitioning (qualitative): Prefers membrane phase; PEG projects into aqueous phase, minimizing nonspecific adsorption.

Note: Exact numeric values vary with solvent, lipid composition, and the specific Cy5/PEG linkage chemistry.

Quality and Grades

• Item-specific grade/purity: Not specified for this item; refer to CoA/Spec Sheet.

How to interpret quality for PEGylated lipids with fluorophores (general guidance for professional users):

• Polymer-average MW: Listed as 5000 Da refers to the nominal PEG chain average; DSPE and Cy5 add additional mass. A distribution (polydispersity) is inherent to PEG-based materials; LC–MS or MALDI–TOF typically shows a Gaussian envelope.
• Degree of labeling: For DSPE-PEG-Cy5, the dye is typically present at a 1:1 ratio to PEG chains (end-functional), but verification by UV–Vis (Cy5 ε) and NMR is standard practice. CoA may include substitution efficiency; check before quantitative fluorescence work.
• Residual solvents and salts: Trace chloroform, methanol, or coupling reagents may be present at low levels. HPLC/LC–MS, 1H NMR (integration of PEG/DSPE resonances), and KF moisture are common QC tools. Item-specific limits are not provided here.
• Functional integrity: Fluorophore purity (minimal free dye) is important to avoid artifactual signal in release assays. SEC or dialysis tests can detect free dye.
• UV cutoffs/metal limits/peroxide levels: Not specified for this item; refer to CoA/Spec Sheet.

Practical note: For reproducible labeling of liposomes/LNPs, verify lot-to-lot consistency by recording the specific absorbance (A650 per mg/mL) under a defined solvent condition (e.g., CHCl3 or DMSO) and normalize dosing by moles of dye-lipid rather than by mass.

Reaction and Applications

Primary use is as a fluorescent lipid component rather than a stoichiometric reagent. Typical research applications (general literature):

• Fluorescent liposomes and lipid nanoparticles

  • Dope at 0.1–2.0 mol% relative to total lipid to visualize particles by fluorescence imaging, quantify recovery, or track stability and leakage (use low mol% to minimize photophysical self-quenching).
  • Incorporation routes: Thin-film hydration/extrusion, microfluidic ethanol injection, or post-insertion from DMSO stocks into pre-formed vesicles above Tm.

• Supported lipid bilayers and GUVs

  • Include trace levels (≤0.5 mol%) to image membrane morphology and dynamics. PEG spacer reduces dye–surface interactions and protein fouling.

• Micelles and polymer–lipid assemblies

  • Forms Cy5-labeled micelles useful for uptake studies, flow tracking in microfluidics, or FRET pairs with complementary dyes (e.g., Cy3) in mixed membranes.

• Analytical readouts

  • Cy5 absorption/emission enables UV–Vis and fluorescence quantification of lipid content; standard curves in matching solvent (e.g., CHCl3 or DMSO) recommended.

Practical tips (literature):

• Protect from light throughout. Mix thoroughly with other lipids in organic solvent before film formation to avoid domain segregation. Remove solvent under reduced pressure followed by high-vacuum desiccation (≥2 h) to minimize residual solvent quenching. Hydrate and process above DSPE Tm for homogeneous incorporation. If self-quenching is suspected, reduce mol% or measure fluorescence after detergent solubilization to estimate actual dye content.

Reaction Conditions

Conventional chemical reaction conditions are not the focus for this product. Instead, conditions pertain to assembly of lipid structures (general literature guidance):

• Thin-film hydration and extrusion

  • Dissolve lipids (including DSPE-PEG-Cy5) in CHCl3:MeOH, cast a thin film, and dry thoroughly (rotary evaporation followed by ≥2 h high vacuum). Hydrate with warm buffer (≥60–70 °C for DSPE-rich mixes) at a total lipid concentration of 1–20 mM; vortex/sonicate. Extrude through polycarbonate membranes (e.g., 100 nm) while maintaining temperature above Tm. Typical recovery yields >70% for well-optimized processes.

• Ethanol injection / microfluidic mixing

  • Prepare lipids in ethanol (including dye-lipid at desired mol%) and inject into aqueous buffer under rapid mixing to form nanoparticles; control flow rate ratio and total flow to tune size. Remove ethanol by dialysis or diafiltration.

• Post-insertion

  • Add a DMSO stock of DSPE-PEG-Cy5 to pre-formed vesicles at 0.2–1.0 mol% while maintaining temperature above DSPE Tm; incubate 15–60 min with gentle mixing; remove DMSO by buffer exchange.

• Photophysics

  • Measure fluorescence with excitation ~646–650 nm and emission collection ~660–700 nm (literature). Use low illumination and oxygen-scavenging systems if photostability is critical.

All parameters above are general, literature-based guidance and should be optimized for specific lipid compositions, equipment, and scale.

Safety and Handling

Authoritative safety information is provided in the product-specific SDS. The following are general precautions for PEGylated lipids with cyanine dyes.

• GHS classification, signal word, pictograms, H-statements: Not specified for this item; refer to SDS/CoA.
• Primary hazards (general): Low volatility; dust/particulate may irritate eyes/respiratory tract. Organic dye can stain skin and equipment; photosensitive. Organic solvents used for dissolution (e.g., chloroform, DCM, DMSO) carry their own hazards.
• PPE: Safety glasses, lab coat, and nitrile gloves. Use amber/light-protective containers. Handle in a fume hood when using volatile organic solvents.
• Incompatibilities: Strong oxidizers; strong acids/bases may hydrolyze ester/phosphate linkages. Avoid reactive decolorants/bleach (will destroy Cy5). Avoid prolonged light and elevated temperatures.
• Safe handling tips:
  • Minimize light exposure (wrap vials in foil; use amber glass).
  • Avoid repeated freeze–thaw of solutions; aliquot stocks.
  • When preparing thin films from chlorinated solvents, employ proper ventilation and solvent traps.
• First aid (general):
  • Skin/eye contact: Rinse with water for at least 15 minutes; remove contaminated clothing; seek medical attention if irritation persists.
  • Inhalation (dust/solvent vapors): Move to fresh air; obtain medical attention if symptoms develop.
  • Ingestion: Rinse mouth; seek medical advice.
• Waste: Treat as organic dye-containing chemical waste; collect solvent rinses separately per institutional and local regulations.

Solvent Selection

DSPE-PEG-Cy5 behaves like a PEGylated phospholipid with a hydrophobic anchor and hydrophilic corona. Solvent choice depends on whether you are: (a) casting thin films/co-formulating with other lipids, or (b) preparing concentrated stocks for post-insertion or micellization.

• Film-casting and co-formulation (literature best practices)

  • Preferred solvents: Chloroform or chloroform:methanol (9:1 to 2:1) provide excellent solubilization for DSPE, PEG segment, and Cy5. DCM can work but evaporates faster and can trap in films.
  • Alternatives: Anhydrous ethanol or isopropanol for greener workflows; may need warming and longer drying to avoid residuals.
  • Avoid: Pure hexanes or very nonpolar alkanes (poor PEG/dye solubility).

• Stock solutions for post-insertion/micelles

  • DMSO or DMF: Good for making 1–10 mg/mL stocks; inject into warm buffer containing pre-formed liposomes, then dialyze/remove cosolvent.
  • Aqueous: Direct dissolution is poor; instead, disperse into warm buffer (>60–70 °C for DSPE-rich systems) with sonication or use detergents (e.g., OG) followed by detergent removal.

• Miscibility and polarity (general)

  • Amphiphilic; partitions strongly into lipid phases. PEG segment prefers polar media; DSPE anchors in hydrophobic phases.

Comparison tip (literature): Versus free Cy5-NHS in DMSO, DSPE-PEG-Cy5 requires amphiphile-aware handling. Versus DSPE-PEG without dye, expect slightly lower solubility in alcohols and stronger visible absorption necessitating light protection.

Storage and Reconstitution

• Item-specific storage conditions: Store at -20 °C (per Product Data). Shipped in ice chest with ice pads. Protect from light at all times.

• General storage guidance (literature/best practice)

  • Keep dry under inert gas (argon/nitrogen) to limit oxidation/hydrolysis. Use amber vials or wrap in foil. Avoid moisture ingress to prevent PEG hydration and clumping.
  • Avoid repeated freeze–thaw of solutions; prepare single-use aliquots.

• Reconstitution (general)

  • For film-casting: Dissolve the solid in anhydrous chloroform or CHCl3:MeOH (9:1) at 1–10 mg/mL. After combining with other lipids, evaporate solvent thoroughly and desiccate before hydration.
  • For stock solutions: Prepare 1–5 mg/mL in anhydrous DMSO or DMF. Store small aliquots at −20 °C, protected from light. Warm to room temperature before opening to minimize condensation.
  • For aqueous dispersions: Incorporate into liposomes or micelles; direct dissolution in water is inefficient. Hydrate and process above DSPE Tm for DSPE-rich systems.

• Stability considerations

  • Cy5 is photosensitive; minimize light exposure during handling and storage.
  • Monitor for free dye release over time using SEC or dialysis; re-purify if needed for quantitative applications.

Any unspecified parameters (e.g., exact shelf life, water content, residual solvent limits) are not specified for this item; refer to the product CoA/Spec Sheet and SDS for authoritative guidance.

Structure and Identity

DSPE-PEG-Cy5, MW 5000, is an amphiphilic, PEGylated phospholipid bearing a lipophilic DSPE anchor and a terminal cyanine-5 (Cy5) fluorophore. It is intended for research use in constructing fluorescently traceable lipid assemblies (e.g., liposomes, micelles, lipid nanoparticles).

• Item-specific identifiers

  • SKU: D1439604
  • Product name: DSPE-PEG-Cy5, MW 5000
  • CAS: D1439604 (catalog identifier)
  • Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Nominal 5000 Da (polymer-average; PEG polydispersity expected)
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.

• Structural features (general/literature description)

  • Hydrophobic domain: DSPE = 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (two saturated C18 chains) that embed stably in lipid bilayers.
  • Hydrophilic spacer: Poly(ethylene glycol) chain (avg. ~5 kDa), conferring steric stabilization and aqueous colloidal stability; provides distance between bilayer surface and dye.
  • Reporter: Cy5 (heptamethine cyanine) fluorophore covalently conjugated to the PEG terminus for far-red fluorescence.
  • Overall topology (2D verbal): Two parallel C18 alkyl chains attached to a glycerol backbone → phosphate → ethanolamine linkage → PEG chain (flexible coil) → terminal Cy5 chromophore.

• Stereochemistry (general)

  • DSPE typically employs the sn-glycerol stereochemistry; the PEG segment is atactic (no defined stereocenters). The material is polydisperse due to PEG.

• Functional group summary

  • Ester linkages (acyl-glycerol), phosphate/ionic headgroup, secondary amine (ethanolamine), ether repeats (PEG), and polymethine chromophore (Cy5).

Synthetic Utility

This material is not typically used as a synthetic reagent for bond-forming organic reactions. Its utility is in supramolecular assembly and materials construction. General/literature use cases:

• Building block for functional membranes

  • Acts as a modular amphiphile combining a bilayer anchor (DSPE), a stealth spacer (PEG), and an optical reporter (Cy5). Useful in designing membranes with controlled surface functionalities and readouts.

• Surface modification

  • Adsorption or insertion into supported lipid bilayers on silica/mica, enabling patterning and fluorescence imaging of model membranes, biosensors, or nanostructured interfaces.

• Retrosynthetic perspective (conceptual)

  • The molecule is conceptually composed of: DSPE–PEG–Cy5 assembled via amide/urea or click-type linkages at PEG termini. While not recommended for further chemical transformation, analogous chemistry is used in the production of such conjugates (e.g., coupling Cy5-NHS to amine-terminated DSPE-PEG).

• Photophysical probe integration

  • Provides a handle for FRET, FRAP, and single-particle tracking experiments when co-assembled with other functionalized lipids (e.g., biotinylated lipids for streptavidin capture), enabling multifaceted assays of membrane behavior.

If covalent modification is desired, start from appropriate reactive precursors (e.g., DSPE-PEG-NH2 or DSPE-PEG-azide) rather than altering the finished DSPE-PEG-Cy5, to avoid degrading the dye or disrupting amphiphilicity.

Target Specificity

Not an antibody or affinity reagent; no biological target specificity is inherent to DSPE-PEG-Cy5. The Cy5 label provides optical detectability but does not confer specific binding to biomolecular targets. If target engagement is required, combine with receptor-binding lipids or ligands in the formulation.