Product Information

NANOGOLD® is a newly developed gold label, prepared using a discrete gold compound rather than a colloid.1 This kit contains the NANOGOLD® particle with a single maleimide functionality incorporated into a ligand on the surface of the gold particle; this has a specific reactivity towards sulfhydryl groups, and may be covalently linked to reduced disulfides in the hinge region of antibodies, as shown in the figure below (Figure 1). It may also be used to label cysteine residues in proteins, or other biomolecules with an accessible sulfhydryl group. Molecules which have been labeled using Monomaleimido-NANOGOLD® include proteins,² peptides,³ and oligonucleotides.⁴ The reagent as supplied has been lyophilized from 0.02 M sodium phosphate at pH 6.5, with 150 mM sodium chloride; dissolution in 1 ml deionized water will produce a solution of activated NANOGOLD® in this buffer. NANOGOLD® conjugates can be used in immunoblotting, light microscopy, and electron microscopy to provide clear visibility. They are stable to wide ranges of pH and ionic strength, and are not radioactive or carcinogenic. The labeling reagent should be stored at -20°C.

Figure 1: Schematic showing NANOGOLD® labeling of Fab fragment via reaction of a sulfhydryl and a maleimide group.

5 vials of reagent are supplied, each containing sufficient reagent to label up to 3 nmol of sulfhydryl groups; this corresponds to 0.15 mg of Fab fragments, or 0.45 mg of IgG molecules.