Update profile
    Change password
    Sign out

Our content has moved! Check out our protein biology page on lifetechnologies.com  Go now >

Methyl-PEG-Lipoamide Compounds

A polyethylene glycol pegylation reagent with a bidentate thiol group for coating metal surfaces.

Pierce ML(PEG)4

Thermo Scientific Pierce ML(PEG)4, or methyl-PEG4-lipoamide, is a methyl- and bidentate thiol-terminated compound that contains a 4-unit polyethylene glycol (PEG) spacer and is used to modify quantum dots, silver and gold surfaces and magnetic particles.

ML(PEG)4 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 polyethylene glycol spacers such as this one significantly reduces nonspecific protein binding.


  • Metal-binding – terminal bidentate thiol reacts spontaneously with silver, gold and other metal surfaces to form strong dative bonds
  • Methyl – terminal methyl group is unreactive, the primary function of this compound being to coat quantum dot and other surfaces to reduce nonspecific binding in assays
  • Polyethylene glycol – PEG groups are flexible, non-immunogenic, hydrophilic, and significantly reduce nonspecific binding of surfaces for protein methods
  • Spacer arm – four-unit PEG spacer makes compound nearly 24 angstroms long

Product Details:

Methyl-PEG4-lipoamide; ML(PEG)4

Chemical structure and properties of ML(PEG)4:

  • Alternative name: Methyl-PEG4-Lipoamide
  • Chemical name: 5-(1,2-dithiolan-3-yl)-N-(2,5,8,11-tetraoxatridecan-13-yl)pentanamide
  • Chemical formula: C17H33NO5S2
  • Molecular weight: 395.58
  • Spacer arm: 23.6 angstroms
  • Form: clear to pale yellow liquid
  • 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.

Pegylated metal surface with methyl-PEG-lipoamide
Modification of metal surfaces with ML(PEG)4 and CL(PEG)12 pegylation reagents.

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.

General References:

  1. Prime, K.L. and Whitesides, G.M. (1991). Self-assembled organic monolayers: model systems for studying absorption of proteins at surfaces. Science 252:1164.
  2. 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.
  3. Lin, P-C., et al. (2006). Ethylene glycol-protected magnetic nanoparticles for a multiplexed immunoassay in human plasma. Small 2(4):485-9.
  4. Zheng, M., et al. (2003). Ethylene glycol monolayer protected nanoparticles for eliminating nonspecific binding with biological molecules. J Am Chem Soc 125:7790-1.
  5. Verma, A. and Rotello, V.M. (2005). Surface recognition of biomacromolecules using nanoparticle receptors. Chem Commun 3:303-12.
  6. 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.

Related Products:

Protein PEGylation technical guide (and PEG reagent selection guide)

Ordering Information
Product # Description Pkg. Size Instructions MSDS CofA Price
26134 ML(PEG)4
Formulation: 4-unit ethyleneglycol functionalized with methyl and bidentate thiol ends; pale liquid
Sufficient For: 10mL of typical 1X (25mM) reaction solution
100mg Product Instructions for product #26134 ML(PEG)4 MSDS for product #26134 ML(PEG)4 Certificate of Analysis for product #26134 ML(PEG)4 $220.00

Now available on lifetechnologies.com

Instructions | MSDS | CofA
Product Instructions | MSDS | CofA  

Recommend this page

Follow Us
Email Sign-up  Email Announcements

You may also need
88605 - Western Blotting Filter Paper, Extra Thick, 7cm x 8.4cm

88404 - Slide-A-Lyzer MINI Dialysis Device, 10K MWCO, 2mL

87732 - Slide-A-Lyzer G2 Dialysis Cassettes, 10K MWCO, 30mL

88405 - Slide-A-Lyzer MINI Dialysis Device, 20K MWCO, 2mL


Antibodies  |   Molecular Biology   |   Cell Biology   |  Thermo Scientific  |   * Trademarks  |   Privacy Statement
© 2015 Thermo Fisher Scientific Inc.   |   3747 N Meridian Rd, Rockford, IL USA 61101   |   1-800-874-3723  or  815-968-0747