- Our famous 1.4 nm Nanogold® label, with a single sulfo-NHS reactive group (sulfo-N-hydroxysuccinimide ester)
- Reacts with primary amines under mild conditions (pH 7.5 to 8.2).
Covalent stability, amazing penetration
The result is stable, covalent attachment of the Nanogold® to a protein, lipid, peptide, modified oligonucleotide or other amine-containing molecule to give a unique gold probe without the problems associated with colloidal gold (aggregation, poor stability, and low penetration).
Easy enhancement for any modality
Nanogold® is readily enhanced with a silver developer (LI Silver or HQ Silver) so that the small gold particles are easily visualized by EM or light microscopy, or by eye on blots and gels.
Mono-Sulfo-NHS-Nanogold® is easy to use
The dry labeling reagent is dissolved in a small amount of DMSO or isopropanol, reconstituted with water and mixed with the molecule to be labeled. Reaction is complete in a few hours, and the labeled conjugate is purified chromatographically by gel filtration.
Applications:
- Label proteins which do not contain a cysteine.
- Label peptides at the N-terminal (see Segond von Banchet, G., and Heppelman, B.: J. Histochem. Cytochem., 43, 821 (1995)).
- Use Fv antibody fragments to prepare the smallest antibody probes (see Ribrioux, S., et al.: J. Histochem. Cytochem., 44, 207-213 (1996)).
- Label small molecules as inhibitors or substrate analogs.
- Label amino-substituted lipids for insertion into liposomes.
Need an even smaller probe? Try our 0.8 nm Mono-Sulfo-NHS-Undecagold
1.4 nm Nanogold® Labeling Reagents
Nanogold® is a better gold label.
The 1.4 nm Nanogold® particle is a gold compound: it is not just adsorbed to proteins, like colloidal gold, but covalently reacts at specific sites under mild buffer conditions. This gives a well defined product that can be purified chromatographically.
Nanogold® brings the versatility of fluorescent conjugation to gold labeling.
Label virtually any molecule
Label any molecule with a suitable reactive group: oligonucleotides, lipids, peptides, proteins, enzyme inhibitors and others. This is a big improvement over colloidal gold, which may be adsorbed only to antibodies and a limited range of proteins and peptides.
Nanogold® is small and highly uniform in size, in sharp contrast to small colloidal gold preparations (most commonly used “1 nm” colloidal golds actually range from 1 to 3 nm).
Label your own biomolecules with our Nanogold® labeling reagents,
or check out our range of antibody IgG, Fab’ and streptavidin Conjugates with Nanogold®.
Left: Silver-enhanced Nanogold®-labeled K+ channel Kv2.1 subunit in rat brain, X15,000 (J.-H. Tao-Cheng, NIH).
Right: Darkfield STEM micrographs of Maleimido Nanogold® labeled A β peptide targeting proteasomes; sample was stained with methylamine vanadate. White dots are 1.4 nm Nanogold®.From Gregori, L., Hainfeld, J.F., Simon, M.N., and Goldgaber, D. (1997). Binding of amyloid beta protein to the 20S proteasome. J. Biol. Chem. 272, 58-62.
Easily enhanced for electron microscopy, light microscopy, cryo-EM, blots…
Try our precision nanoparticle developers for slow development with low background!
Features and Advantages
- Unparalleled penetration of conjugates -up to 40 µm!
- Higher density of immunolabeling than with larger gold probes.
- Can be conjugated to any molecule with a suitable reactive group. Available with different reactivities.
- Extremely uniform 1.4 nm gold particle.
- Label at specific sites which do not obstruct native reactivity.
- Close to stoichiometric labeling.
- Reacts under mild, neutral conditions.
- Conjugates are easily isolated by gel filtration.
- Conjugates are stable to a wide range of pH and ionic strengths.
- High stability: conjugates show unchanged reactivity after storage for a year.
