Poly-L-Lysine solution - Molecular weight: 150000-300000，0.1 % (w/v) in H2O , CAS No.25988-63-0

CAS: 25988-63-0 Cat. No.: P303253 Formula: L-Lys-(L-Lys)n-L-Lys•xHBr

QUALITÀ & PUREZZA Molecular weight: 150000-300000，0.1 % (w/v) in H2O

Synonyms

2olb | DTXSID40948891 | L-Lysine, L-lysyl-L-lysyl- | Lys-Lys-Lys | Y7F82M80K8 | SCHEMBL3796535 | (S)-6-Amino-2-((S)-6-amino-2-((S)-2,6-diaminohexanamido)hexanamido)hexanoic acid | Lysyllysyllysine | lysyl-lysyl-lysine | L-Lysine,L-lysyl-L-lysyl- | (2S)-6-

Storage

Store at 2-8°C

Shipped In

Wet ice

Panoramica

Preparation Note

This product is supplied as a 0.10% (w/v) solution in water. Coating slides with this solution should be followed with a 5 minute incubation and drying the slides at room temperature. Coated slides will be stable for one year if protected from dust.

Other Notes

Poly-L-lysine is a positively charged amino acid polymer with approximately one HBr per lysine residue. The hydrobromide allows the poly-L-lysine to be in a crystalline form soluble in water. A small amount of product may be found in the beta structure because the HBr interferes with hydrogen bonding between amino and either the carboxyl groups or N or O containing moieties.

Specifiche

Sinonimi

2olb | DTXSID40948891 | L-Lysine, L-lysyl-L-lysyl- | Lys-Lys-Lys | Y7F82M80K8 | SCHEMBL3796535 | (S)-6-Amino-2-((S)-6-amino-2-((S)-2,6-diaminohexanamido)hexanamido)hexanoic acid | Lysyllysyllysine | lysyl-lysyl-lysine | L-Lysine,L-lysyl-L-lysyl- | (2S)-6-

Specifiche e purezza

Molecular weight: 150000-300000，0.1 % (w/v) in H2O

Meccanismi biochimici e fisiologici

Poly-L-lysine is a nonspecific attachment factor for cells useful in promoting cell adhesion to solid substrates by enhancing electrostatic interaction between negatively charged ions of the cell membrane and the culture surface. When it is absorbed to th

Condizioni di conservazione di stoccaggio

Store at 2-8°C

Spedito in

Wet ice

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Tipo di azione

ACTIVATOR

Nomi e identificatori

Pubchem Sid

488184689

Pubchem Sid Url

https://pubchem.ncbi.nlm.nih.gov/substance/488184689

Sorrisi canonici

C(CCN)CC(C(=O)NC(CCCCN)C(=O)NC(CCCCN)C(=O)O)N

IUPAC Name

(2S)-6-amino-2-[[(2S)-6-amino-2-[[(2S)-2,6-diaminohexanoyl]amino]hexanoyl]amino]hexanoic acid

InChIKey

WBSCNDJQPKSPII-KKUMJFAQSA-N

INCHI

1S/C18H38N6O4/c19-10-4-1-7-13(22)16(25)23-14(8-2-5-11-20)17(26)24-15(18(27)28)9-3-6-12-21/h13-15H,1-12,19-22H2,(H,23,25)(H,24,26)(H,27,28)/t13-,14-,15-/m0/s1

Isomeri SMILES

C(CCN)C[C@@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)O)N

Termini MeSH

L-Lys-(L-Lys)n-L-Lys•xHBr

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Organic acids and derivatives
    • Classe Carboxylic acids and derivatives
      • Subclass Amino acids, peptides, and analogues
        • Level5 Peptides
          • Level6 Oligopeptides

• Kingdom: Organic compounds
• Superclass: Organic acids and derivatives
• Classe: Carboxylic acids and derivatives
• Subclass: Amino acids, peptides, and analogues
• Intermediate Tree Nodes: Peptides
• Direct Parent: Oligopeptides
• Alternative Parents: N-acyl-L-alpha-amino acids Alpha amino acid amides Medium-chain fatty acids Amino fatty acids N-acyl amines Secondary carboxylic acid amides Amino acids Monocarboxylic acids and derivatives Carboxylic acids Organopnictogen compounds Organic oxides Monoalkylamines Hydrocarbon derivatives Carbonyl compounds
• Molecular Framework: Aliphatic acyclic compounds
• Substituents: Alpha-oligopeptide - N-acyl-alpha-amino acid - N-acyl-alpha amino acid or derivatives - N-acyl-l-alpha-amino acid - Alpha-amino acid amide - N-substituted-alpha-amino acid - Alpha-amino acid or derivatives - Medium-chain fatty acid - Amino fatty acid - Fatty amide - N-acyl-amine - Fatty acyl - Fatty acid - Secondary carboxylic acid amide - Amino acid or derivatives - Carboxamide group - Amino acid - Carboxylic acid - Monocarboxylic acid or derivatives - Organopnictogen compound - Primary aliphatic amine - Organic nitrogen compound - Hydrocarbon derivative - Carbonyl group - Organic oxide - Organonitrogen compound - Amine - Primary amine - Organooxygen compound - Organic oxygen compound - Aliphatic acyclic compound
• Descrizione: This compound belongs to the class of organic compounds known as oligopeptides. These are organic compounds containing a sequence of between three and ten alpha-amino acids joined by peptide bonds.
• External Descriptors: Not available

Data sources

1. Djoumbou Feunang Y, Eisner R, Knox C, Chepelev L, Hastings J, Owen G, Fahy E, Steinbeck C, Subramanian S, Bolton E, Greiner R, and Wishart DS. ClassyFire: Automated Chemical Classification With A Comprehensive, Computable Taxonomy. Journal of Cheminformatics, 2016, 8:61.

DOI: 10.1186/s13321-016-0174-y

Proprietà chimiche e fisiche

• Peso molecolare: 402.500 g/mol
• XLogP3: -5.600
• Hydrogen Bond Donor Count: 7
• Hydrogen Bond Acceptor Count: 8
• Rotatable Bond Count: 17
• Exact Mass: 402.295 Da
• Monoisotopic Mass: 402.295 Da
• Topological Polar Surface Area: 200.000 Ų
• Heavy Atom Count: 28
• Formal Charge: 0
• Complexity: 463.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 3
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 1

Application Protocols

The following protocols provide general, literature-based guidance for using poly-L-lysine solutions in research. They are not validated for this specific item; adjust based on the CoA (concentration, MW) and your experimental needs.

A. Coating tissue-culture-treated plastic or glass

• Dilute to 10–50 µg/mL in sterile water or PBS (optimize 5–100 µg/mL range as needed).
• Add sufficient volume to fully cover the surface (e.g., 0.1 mL/cm2 for dishes).
• Incubate 30–60 minutes at room temperature (glass may benefit from up to 2 h).
• Aspirate and rinse 2–3× with sterile water or buffer. Allow to air-dry in a biosafety cabinet if desired. Use promptly or store coated ware at 2–8°C sealed and sterile for up to 1–2 weeks (practices vary).

B. Preparing polyplexes with plasmid DNA (research)

• Prepare DNA in low-salt buffer (e.g., 10 mM HEPES, pH ~7.4). Calculate N/P ratio (5–20 typical starting range).
• Slowly add PLL solution to DNA while gently vortexing. Incubate 15–30 minutes at room temperature.
• Characterize particle size/zeta potential as needed; adjust N/P and ionic strength to tune properties.

C. Layer-by-layer film assembly

• Prepare 0.1–1.0 mg/mL PLL and a complementary polyanion (e.g., PSS, alginate) in 10–150 mM NaCl, pH 6–7.4.
• Immerse substrate for 10 minutes in PLL, rinse thoroughly, then 10 minutes in polyanion; repeat for desired bilayers.

Sterility note: For cell culture, use sterile technique and sterile-filter working solutions when possible.

These are general protocols; consult the SDS/CoA for any item-specific constraints.

Biological Roles

Poly-L-lysine is not a native biological polymer (the natural counterpart is polypeptides with varied sequences), but its structure comprises repeats of the amino acid L-lysine, a canonical proteinogenic amino acid.

General/literature context (not product-specific):

• Electrostatics and cell adhesion: The dense array of protonated ε-amino groups provides strong cationic charge, promoting adsorption to negatively charged cellular and extracellular surfaces (e.g., sialic acids, proteoglycans). This facilitates cell attachment to otherwise non-adhesive substrates in vitro.
• Biomolecular interactions: PLL binds anionic macromolecules, including nucleic acids and glycosaminoglycans, enabling formation of polyplexes and multilayer films used in biomaterials and surface engineering.
• Enzymatic susceptibility: Being composed of L-residues, PLL can be susceptible to proteolytic degradation by some extracellular proteases; this is reduced with the D-enantiomer (PDL).
• Influence on cell behavior: Surface-immobilized PLL enhances initial adhesion and spreading for many adherent cell types. However, high local cationic charge in solution can be cytotoxic; optimal concentrations mitigate adverse effects (literature trends).
• Antimicrobial surface research: Cationic polymers including PLL have been investigated for contact-active antimicrobial coatings by disrupting bacterial membranes; effectiveness depends on molecular weight, density, and immobilization strategy (literature, research use only).

Note: These are generalized roles reported in the biomaterials and cell culture literature and are not specific performance claims for this catalog item.

Buffer Applications

Not typically applicable. Poly-L-lysine is a cationic polymer used for surface coating and polyelectrolyte complexation rather than as a buffering agent.

Practical notes (literature; not product-specific):

• Working solutions are commonly prepared in water or simple buffers (e.g., PBS) for coating steps. Ionic strength and pH modulate adsorption; low ionic strength (≤50–100 mM salt) generally favors stronger surface binding.
• If covalent immobilization is planned (e.g., with glutaraldehyde), perform the coating in a compatible buffer (often phosphate-based) free of competing amines.

For buffer recipes, consult your specific downstream application; this product does not define a buffering system.

Green Alternatives

Context: Poly-L-lysine solutions are water-based and used at low concentrations, aligning well with green chemistry principles of safer solvents and benign auxiliaries. Environmental considerations focus on resource origin, biodegradability, and cytotoxicity.

Greener or alternative choices (literature; trade-offs noted):

• Poly-D-lysine (PDL): Protease-resistant synthetic enantiomer; offers longer-lasting coatings. Trade-off: Not naturally occurring enantiomer; similar cytotoxicity profiles at high dose.
• ECM-derived coatings (collagen, laminin, fibronectin, vitronectin): Biologically sourced and often biodegradable; provide specific adhesion motifs (e.g., RGD). Trade-off: Animal-origin risks, batch variability, higher cost, cold-chain reliance.
• Recombinant peptides or synthetic RGD-peptides: Defined composition, animal-free options; can be immobilized covalently. Trade-off: Specialized handling, cost.
• Poly(ethyleneimine) (PEI) or chitosan: Alternative cationic polymers; chitosan is biobased and biodegradable. Trade-offs: PEI can be more cytotoxic; chitosan requires acidic conditions and has solubility limits.

Small comparison (general; not product-specific):

• PLL: Water-based, rapid adsorption, widely validated; potential cytotoxicity at high MW/concentration.
• PDL: Greater proteolytic stability; similar handling and environmental profile.
• Chitosan: Renewable and biodegradable; needs acidic media for dissolution; different surface chemistry.
• ECM proteins: Highest biofunctionality; variability and sourcing concerns.

Recommendation: For labs emphasizing green practices, start with aqueous PLL/PDL at the lowest effective concentration and consider recombinant peptide coatings when cell-type-specific cues are required without animal sourcing.

Pharmaceutical Uses

No therapeutic claims are made. The following reflects general formulation and manufacturing research uses reported in the literature and does not pertain to clinical application.

Literature/formulation context (not product-specific):

• Device and component coating: PLL has been investigated as a primer layer on diagnostic device surfaces to enhance biomolecule immobilization (e.g., capture antibodies, nucleic acids) in analytical assays.
• Excipient in research prototypes: As a cationic polyelectrolyte, PLL is studied for microencapsulation and as a component of polyelectrolyte multilayer coatings on particles or implants to modulate surface charge and adsorption.
• Gene delivery research: Formation of PLL–DNA/RNA polyplexes has been explored as a non-viral vector strategy; variables include MW, N/P ratio, and ionic strength (research use only).
• Antifouling/antimicrobial surface strategies: Immobilized cationic layers, including PLL derivatives, have been studied to reduce microbial colonization on materials; efficacy depends strongly on surface chemistry and immobilization density.

Regulatory/status notes:

• Pharmacopeial monographs for PLL are not broadly established; material is typically specified by MW range, sterility/endotoxin limits, and residual solvent/salt content in research contexts.

This catalog item is for research use only and not for use in humans or diagnostic procedures.

Physical Properties

Item-specific specifications

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Concentration/grade/purity: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight distribution (Mw/Mn, kDa range): Not specified for this item; refer to CoA/Spec Sheet.

General/literature characteristics for poly-L-lysine solutions (for context; not product specs):

• Physical state: Aqueous solution of a hygroscopic, polycationic polypeptide; often clear to slightly opalescent depending on MW and concentration.
• Solubility: Freely soluble in water and most physiological buffers at neutral to mildly acidic pH; insoluble in typical organic solvents (e.g., alcohols, ethers, hydrocarbons). Enhanced solubility under acidic conditions due to full protonation of ε-NH3+.
• pKa (ε-amine of lysine side chain, monomeric lysine): ~10.3–10.8 (literature). Effective protonation of PLL side chains persists to basic pH.
• Isoelectric properties: Strongly cationic across a wide pH range; effective positive charge density decreases as pH approaches and exceeds ~10 (literature).
• Viscosity: Strongly dependent on concentration and MW (higher MW gives higher intrinsic viscosity and solution stringiness; literature).
• Density/refractive index/UV cutoff: Not specified for this item; refer to CoA/Spec Sheet. (No characteristic small-molecule values; polymer and formulation dependent.)
• Thermal transitions: No discrete boiling/melting point; thermal degradation precedes melting for dry polymer. Aqueous solutions are typically used at ambient temperatures (literature).

Note: Exact values depend on degree of polymerization, counterion, and concentration; consult the CoA for item-specific metrics.

Quality and Grades

Item-specific quality details

• Grade/purity: Not specified for this item; refer to CoA/Spec Sheet.
• Sterility/endotoxin status: Not specified for this item; refer to CoA/Spec Sheet.
• Concentration and MW range: Not specified for this item; refer to CoA/Spec Sheet.

Context and typical grade definitions (general; not product-specific):

• Cell culture grade: Sterile-filtered, low bioburden, and often accompanied by endotoxin limits (e.g., <0.25 EU/mL). Used for surface coating to enhance attachment of adherent or primary cells (including neurons and glia) in research.
• Molecular biology grade: DNase/RNase-free status may be indicated when PLL is used for nucleic acid complexation or surface capture applications.
• MW designation: Vendors often offer low (~1–5 kDa), medium (~30–70 kDa), and high (>150–300+ kDa) MW PLL. Higher MW enhances surface charge density and adhesion but may increase cytotoxicity; lower MW offers gentler cell compatibility for some applications (literature trends).
• Counterion/salt form: Free base vs. acid/salt (e.g., hydrobromide) can influence solubility, pH, and ionic strength of the working solution.

Implications for selection:

• For sensitive primary cells, users often prefer sterile, endotoxin-controlled PLL at defined MW and concentration.
• For materials assembly (layer-by-layer, microfluidics), tighter MW distribution and defined counterion improve reproducibility.

For this specific catalog item, consult the CoA/Spec Sheet for exact grade, concentration, MW distribution, and sterility testing results.

Reaction and Applications

This material is primarily a biological/materiomics tool rather than a small-molecule reagent. Its “applications” are rooted in electrostatic interactions and interfacial assembly, not classical organic reactions.

Key application areas (literature; not product-specific):

• Cell culture surface coating: Enhances attachment of adherent cells to tissue culture plastic or glass. Particularly useful for neurons, glia, and other weakly adherent or serum-free conditions.
• Polyelectrolyte complexation: Forms complexes with anionic macromolecules (e.g., DNA/RNA, alginate, hyaluronan, heparin). Used in layer-by-layer (LbL) assembly to build nanostructured films and in microcapsule fabrication.
• Micro- and nano-fabrication: Surface priming to improve adsorption of proteins, microcontact-printed patterns, and microfluidic channel treatment to reduce electroosmotic variability.
• Biosensing and biointerfaces: Immobilization scaffold for negatively charged proteins, nucleic acids, and nanoparticles; charge-tuning of surfaces prior to covalent crosslinking (e.g., with glutaraldehyde) for stable functionalization.
• Gene delivery research: Cationic PLL condenses nucleic acids into polyplexes; parameters such as N/P ratio, MW, and salt concentration control particle size and zeta potential (literature).

Practical tips (literature):

• Surface adsorption is stronger at low ionic strength and pH 6–8. Rinse after coating to remove unbound polymer.
• Higher MW and concentration increase coating density but may elevate cytotoxicity. Optimize empirically for each cell type.
• For LbL films, alternate PLL with anionic polyelectrolytes; control film growth via pH and ionic strength.

Note: No classical reaction conditions apply; focus on interfacial assembly and electrostatics.

Reaction Conditions

Classical reaction conditions are not directly applicable; however, common operational conditions for surface coating and conjugation with poly-L-lysine are well established in the literature (general guidance; not product-specific):

Surface coating (cell culture):

• Working concentration: 5–100 µg/mL in sterile water or PBS (typical literature range). Start at 10–50 µg/mL for most adherent cells.
• Incubation: 10–60 minutes at room temperature, or 1–2 hours at room temperature for glass; ensure complete surface coverage.
• Rinse: Remove solution and rinse 2–3× with sterile water or buffer to eliminate unbound polymer before seeding cells.

Layer-by-layer (LbL) assembly:

• Solutions: 0.1–1.0 mg/mL PLL and complementary polyanion in 10–150 mM NaCl, pH 6–7.4.
• Dwell time: 5–15 minutes per layer, with thorough rinses between depositions.

Bioconjugation via NHS-esters:

• Buffer: 10–100 mM phosphate or bicarbonate, pH 7.8–8.5; avoid primary amine buffers (e.g., Tris, glycine).
• Stoichiometry: Adjust equivalents to target DoS; monitor by TNBS assay or ninhydrin for free amines.
• Temperature/time: Room temperature for 0.5–2 hours; keep solutions cooled for sensitive ligands.

DNA/RNA polyplex formation (research):

• N/P ratio: Typically 5–20 (literature), optimized per MW and nucleic acid length.
• Mixing: Add PLL to nucleic acid slowly with gentle vortexing; incubate 15–30 minutes for complex maturation.

Note: Optimize conditions empirically based on MW/concentration of the specific PLL solution. These are general literature values and not specifications for this item.

Safety and Handling

Item-specific hazard information

• GHS classification: Not specified for this item; refer to SDS.
• Signal word: Not specified for this item; refer to SDS.
• Hazard (H) statements: Not specified for this item; refer to SDS.
• Pictograms: Not specified for this item; refer to SDS.

General safety considerations (literature/practice; not product-specific):

• Hazards: Aqueous PLL solutions are typically considered irritants. Cationic polymers can be cytotoxic at elevated concentrations and may cause irritation to skin, eyes, and respiratory tract upon contact or aerosolization.
• PPE: Wear lab coat, nitrile gloves, and safety glasses or face shield when handling. Avoid inhalation of mists/aerosols; work in a chemical fume hood or biosafety cabinet if aerosol generation is possible.
• Incompatibilities: Avoid strong oxidizers and anionic polyelectrolytes/detergents if retention of cationic function is critical (anionic species may form insoluble complexes/precipitates). Avoid contact with reactive carbonyl crosslinkers unless intentionally crosslinking.
• First aid overview: In case of skin/eye contact, rinse with water for at least 15 minutes; remove contaminated clothing. If inhaled, move to fresh air. If ingested, rinse mouth with water. Seek medical attention if symptoms persist. Defer to SDS for definitive instructions.
• Spill/cleanup: Wipe aqueous spills with absorbent; wash area with water. Prevent release of concentrated solutions to drains where cationic polymers may negatively impact biological treatment systems.
• Waste: Dispose according to institutional and local regulations.

Always consult the product-specific SDS for authoritative safety and regulatory guidance.

Solvent Selection

Applicability: This product is supplied as a solution and is typically used as received or diluted in aqueous media. Organic solvent selection is generally not applicable.

General/literature guidance (not product-specific):

• Primary solvent: Water or physiological buffers (e.g., PBS, HBSS) are standard. Acidified water (e.g., 0.1 M acetic acid) can improve solubility of dry PLL; for solutions, maintain the manufacturer’s pH.
• Miscibility: Fully miscible with water; forms insoluble complexes/precipitates with many anionic polymers (e.g., alginate, heparin, DNA) depending on stoichiometry and ionic strength.
• Ionic strength and pH effects: Elevated salt (≥100–150 mM NaCl) screens electrostatic interactions, reducing surface adsorption and complexation. Lower pH increases protonation of ε-NH2 groups, enhancing cationic behavior.

When to choose PLL vs alternatives (literature):

• PLL solution: Rapid, robust enhancement of cell and protein adsorption to negatively charged plastic/glass; widely used for coating cultureware.
• Poly-D-lysine (PDL): Similar charge/adsorption but resistant to proteolysis; often favored for neuronal culture longevity.
• ECM proteins (e.g., collagen, laminin, fibronectin): Provide biochemical cues for specific cell types; may be more expensive and sensitive to storage/sterility.

Comparison (general):

• Charge-only adhesion: PLL/PDL
• Biofunctional signaling: ECM proteins/peptides

Note: For this item, consult the CoA for buffer composition and permissible diluents. If unspecified, perform small-scale compatibility tests before large-scale coating.

Storage and Reconstitution

Item-specific instructions

• Storage conditions: Store at 2–8°C (per Product Data).
• Shipped in: Wet ice (per Product Data).
• Concentration, buffer composition, stabilizers: Not specified for this item; refer to CoA/Spec Sheet.

General guidance for aqueous PLL solutions (not product-specific):

• Do not freeze unless the CoA explicitly permits; repeated freeze–thaw can alter polymer conformation and promote aggregation or container adsorption.
• Protect from microbial contamination. If sterility is required and compatible, work aseptically; consider sterile filtration (0.22 µm) of dilutions.
• Aliquot upon first use to minimize bioburden and repeated warming/cooling cycles. Use low-binding plasticware to reduce adsorption losses, especially at low concentrations.
• Light sensitivity: PLL is not strongly photosensitive, but protect sensitive conjugates (if any) from light.
• Stability: Shelf-life and stability are concentration-, MW-, and buffer-dependent. Monitor for turbidity or precipitation; discard if contamination or instability is observed.

Reconstitution: Not applicable (supplied as a solution). For preparing working solutions, dilute with sterile water or compatible buffer as required by the application, verifying pH and ionic strength to maintain adsorption/performance.

Always refer to the product’s CoA and SDS for definitive, item-specific storage and handling directions.

Structure and Identity

Poly-L-lysine (PLL) solution is a water-based preparation of a polycationic homopolymer composed of L-lysine residues joined by peptide (amide) bonds.

• SKU: P303253
• Product name: Poly-L-Lysine solution
• CAS: 25988-63-0 (poly-L-lysine, mixture; polydisperse)
• InChIKey: 394186 (as provided)
• SMILES: Not specified for this item; refer to CoA/Spec Sheet. (Note: linear polymers typically lack a single definitive SMILES.)
• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet. (Polymeric and DP-dependent.)
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet. (Polydisperse; commonly specified as a range.)

Structural features (general/literature):

• Homopolyamide backbone: –[NH–CHR–CO]n– where R = (CH2)4–NH2 for L-lysine.
• Side chains: ε-amino groups (–NH2) on each lysine, typically protonated under neutral/physiological pH, conferring strong cationic character.
• Stereochemistry: All residues are L-configuration; potential for secondary structure but commonly presents as random coil in aqueous media unless constrained.
• End groups: Typically amine- and carboxyl-terminated (DP-dependent); may be salt forms (e.g., HBr) depending on preparation (not specified for this item).

2D description in words:

• A linear peptide chain of repeating L-lysine units, each containing a chiral center at α-carbon, an amide bond along the main chain, and a four-methylene spacer leading to a terminal ε-amino group that is cationic in water. This dense array of protonated amines yields strong electrostatic interactions with negatively charged surfaces (e.g., glass, polystyrene, cell membranes, nucleic acids).

Synthetic Utility

As a functional macromolecule, poly-L-lysine serves as a versatile scaffold rather than a classical reagent.

Utility in synthesis and materials (literature; not product-specific):

• Reactive handles: Each repeat unit presents a primary ε-amine (and sometimes free α-amine at the terminus), providing sites for covalent modification via NHS-ester acylation, isothiocyanates, aldehyde/ketone conjugation (Schiff base, followed by reductive amination), or carbodiimide coupling to carboxylates.
• Crosslinking: PLL can be crosslinked using dialdehydes (e.g., glutaraldehyde) or multifunctional NHS-esters to yield hydrogels, coatings, or immobilized layers.
• Polyelectrolyte multilayers (LbL): Alternating deposition with anionic polymers (e.g., poly(styrene sulfonate), alginate, hyaluronan) enables nanometer-scale control of film thickness and composition; useful for coatings, capsules, and controlled release.
• Nanoparticle functionalization: Electrostatic adsorption or covalent grafting of PLL onto silica, gold, or polymer nanoparticles imparts positive zeta potential and provides amino functionality for subsequent bioconjugation.
• Template-directed assembly: PLL can direct mineralization (e.g., with silica precursors) or serve as a structure-directing agent for inorganic–organic hybrids via charge interactions.

Considerations:

• Degree of substitution (DoS) control is crucial for reproducibility; titrate equivalents of reactive reagents relative to estimated available amines.
• Maintain pH 7.5–8.5 for NHS ester couplings; avoid buffers with free amines (e.g., Tris) during conjugation. Use phosphate or bicarbonate buffers unless otherwise justified.

These utilities describe general strategies; consult the CoA for this item’s concentration and MW to plan stoichiometry.

Target Specificity

Not applicable. This product is a polymer solution, not an affinity reagent or antibody. It does not possess antigen/epitope specificity, clone, isotype, or species reactivity.

For application-relevant specificity, see sections on Reaction & Applications and Application Protocols describing electrostatic interactions with negatively charged surfaces and biomolecules.