10 nm Ni-NTA-Nanogold NEW

Optimum size for direct EM viualization
Use for post-embedding labeling

Our new 10 nm Ni-NTA-Nanogold® brings optimum EM visualization without silver or gold enhancement, while preserving the high resolution of the original 1.8 nm and 5 nm probes.

The entire probe is similar in size to an unlabeled IgG molecule, but the larger gold particles may be clearly visualized by standard TEM without silver or gold enhancement, even in wider views such as thick sections and whole cells. Blot sensitivity will be even higher that with the smaller sizes due to the larger gold.

• High visibility: the 10 nm gold particle is highly monodisperse and clearly visualized at TEM resolution in most kinds of specimens without silver or gold enhancement.
• Universal probe for labeling any His-tagged fusion proteins: this simplifies labeling as it may be used to label many different targets without the need for generating different antibodies. It may also be used for multiple labeling studies in conjunction with gold particles of different sizes, or with silver or gold-enhanced Nanogold^®.
• Precise labeling resolution: the link between the nitrilotriacetic acid - Ni(II) chelate and gold surface is much smaller than an antibody or protein, and therefore bound gold is located much closer to its target: we estimate that the distance from the gold particle surface to the His tag is on the order of 2 nm. Plus, this is a primary probe: there is no secondary antibody to increase the distance to the target. Use NTA-Ni(II)-Nanogold^® to localize sites in protein complexes or other macromolecular assemblies at molecular resolution.
• High solubility, biocompatibility, and stability:10 nm Ni-NTA-Nanogold^® is prepared using a stable, highly hydrophilic surface functionalization.
• Strong binding: binding constants for Ni(II)-NTA are very high due to the combination of the chelate effect of multiple histidine binding, and target binding of multiple Ni(II)-NTA functionalities. Dissociation constants are estimated to be between 10^-7 to 10^-13 M^-1. For many applications, this provides binding strengths comparable to antibodies.
• High penetration: 10 nm Ni-NTA-Gold is similar in size to an unlabeled antibody IgG molecule, and much smaller than a 10 nm colloidal gold-antibody conjugate. It can therefore penetrate into specimens and access sterically restricted interior sites much better than a 10 nm immunogold probe, without the additional mass of an unlabeled primary, and provide higher labeling density. In some systems it may be used with stronger fixation or less permeabilization, enabling labeling with better ultrastructural preservation.
• Super sensitivity: the larger gold particle provides highest sensitivity with virtually no background when used to detect His-tagged targets on blots.