Thermo Scientific Pierce CL(PEG)12, or carboxy-PEG12-lipoamide, is a carboxyl- and bidentate thiol-terminated compound that contains a 4-unit polyethylene glycol (PEG) spacer and is used to modify quantum dots, and silver or gold surfaces and particles.
CL(PEG)12 is a bidentate thiol-terminated and carboxylic acid pegylation reagent. The PEG compound has a defined molecular weight and spacer length and is useful for modifying surfaces such quantum dots, self-assembled monolayers and magnetic particles. Functionalization of solid surfaces with this polyethylene glycol reagent provides carboxylate "handles" for protein immobilization via EDC crosslinking and significantly reduces nonspecific protein binding and provides.
- Metal-binding – terminal bidentate thiol reacts spontaneously with silver, gold and other metal surfaces to form strong dative bonds
- Carboxylate – terminal carboxylic acid group allows conjugation to amine-containing affinity ligands using carbodiimide (EDC) and Sulfo-NHS crosslinking chemistry
- Polyethylene glycol – PEG groups are flexible, non-immunogenic, hydrophilic, and significantly reduce nonspecific binding of surfaces for protein methods
- Spacer arm – 12-unit PEG spacer makes the reagent nearly 56 angstroms long, minimizing steric hindrance for protein immobilization and binding assays
- Alternative name: Carboxy-PEG12-Lipoamide
- Chemical name: 45-(1,2-dithiolan-3-yl)-41-oxo-4,7,10,13,16,19,22,25,28,31,34,37-dodecaoxa-40-azapentatetracontan-1-oic acid
- Chemical formula: C35H67NO15S2
- Molecular weight: 806.03
- Spacer arm: 55.5 angstroms
- Form: yellow solid
- Solubility: dissolve in DMSO or DMF for use
The use of ML(PEG)4 with CL(PEG)12 in surface modification can form a hydrophilic “lawn” of methyl ether-terminated PEGs with periodic exposed carboxy -containing PEGs. The exposed carboxylic acid groups can be coupled to affinity ligands using the carbodiimide coupling reaction with EDC and sulfo-NHS.
Typical PEG reagents contain heterogeneous mixtures of different PEG chain lengths; however, our PEG reagents are homogenous compounds of defined molecular weight and spacer length, providing precision in optimizing modification applications.
Modification of metal surfaces with Thermo Scientific ML(PEG)4 and CL(PEG)12 pegylation reagents.
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- Bentzen, E.L., et al. (2005). Surface modification to reduce non-specific binding of quantum dots in live cell assays. Bioconjugate Chem 16:1488-94.
- Lin, P-C., et al. (2006). Ethylene glycol-protected magnetic nanoparticles for a multiplexed immunoassay in human plasma. Small 2(4):485-9.
- Zheng, M., et al. (2003). Ethylene glycol monolayer protected nanoparticles for eliminating nonspecific binding with biological molecules. J Am Chem Soc 125:7790-1.
- Verma, A. and Rotello, V.M. (2005). Surface recognition of biomacromolecules using nanoparticle receptors. Chem Commun 3:303-12.
- Kidambi, S., et al. (2004). Selective depositions on polyelectrolyte multilayers: self-assembled monolayers of m-dPEG acid as molecular template. J Am Chem Soc 126:4697-03.
Guide to PEGylation – links to different kinds of polyethylene glycol reagents
Other PEGylation Reagents