Graphene Oxide

Protein modification & bioconjugation service


Proteins are the most common biological molecules that perform a vast array of biological functions within living organisms. Through controlled modification of protein surfaces, these biological molecules can be re-engineered to provide desired functions for biomolecule detection, assay, tracking or targeting.

The most common functional groups for bio-modification on a protein are amine (from Lysine and N-terminus), sulfhydryl (from Cysteine), carboxylic acid (from C-terminus or aspartic and glutamic acid) and hydroxyl from threonine, serine or tyroysine). Chemical modification of above amino acid residues can easily carried out but such modifications are typically non-specific and result in heterogeneous bioconjugates.

Site specific modification provides better control for protein labeling and bio-conjugation. Sulfhydryl based modification is the most common way to do the site specific modification. Typically, sulfhydryl functional group can be derived from Cysteine residue generated from site specific mutagenesis.

Nanocs has been a long time expert in the field of site specific bio-modification and conjugation. During the past decade, we have developed a handful reagents for sulfhydryl modification, generation as well as detection. A number of sulfhydryl reactive reagents, including fluorophores, biotins, PEG derivations, are readily available from our conjugation reagent tool pools.


Protein Service

Service areas:

  • Fluorescent Labeling, including Alexa Fluor, Cy dyes and many other dyes;
  • Pegylation, especially cysteine based site specific labeling;
  • Enzyme and antibody conjugation;
  • Peptide and other biomolecule chemical modification;
  • Particle & bead conjugation;
  • Mutifunctional ligand modification and conjugation.

Competitive advantages:

  • Deep knowledge and rich experience in biomaterial modification and conjugation;
  • Thousands of brand name and in-house fluorophores, biotins, pegylation reagents and particles;
  • Patented reagents and processes for biomodification and conjugation.

Reagents and technologies:

  • SunLightTM Fluorescent molecules;
  • PeGOTM Pegylation reagents and methods;
  • SnapLinkTM Cross linkers;
  • Multifunctional nanoparticles and beads.

For more detailed information, please call us at 1-800-388-4221 or email us at

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