One-step His-tag labeling!
Directly label almost any His-tagged protein for imaging
5 & 10 nm are directly visible in TEM
Easy, precise enhancement for any scope or blots
Designed for detection and localization of His-tagged proteins using electron microscopy, light microscopy, blotting and gels.
Your choice of a precision 1.8, 5 nm or 10 nm Nanogold® gold nanoparticle, with Ni-NTA(nickel (II)-nitrolotriacetic acid) functionality incorporated into the surface ligands.
Ni-NTA functionalities bind to histidines on tagged proteins, forming stable complexes with extremely low dissociation constants.
Ni-NTA specifically binds DIRECTLY to His-tags
NO ANTIBODIES NEEDED!
- Ni-NTA binds fast — no more long incubations!
- Stable gold construct, won’t degrade/denature like antibodies
- Labels under both non-denaturing and denaturing conditions
- Save money and time with Ni-NTA-Nanogold®!
His-tags made simple
Perfect for Cryo-EM
Isolating recombinant proteins with His-tag purification systems is arduous and tends to produce results with poor specificity and lack of visibility under the electron microscope. To overcome these obstacles, we developed a simple reagent capable of labeling almost any His-tagged recombinant protein for imaging, even by electron microscopy.
Using a small nickel compound, the His-tag binds to our versatile Nanogold® label, which remains tightly bound to the target protein with minimal disruption to the system. Our new 5nm and 10 nm Nanogold® labels are large, stable and electron dense– ideal for direct imaging using both light and electron microscopy.
- 10 nm, 5 nm or 1.8 nm sizes for EM, LM, blots and gels
- Tiny probes = highest resolution + deep penetration
- Low background: Super-specific Ni-NTA binding
- Permanent stain. Does not fade; archival
- 5 & 10 nm are directly visible in standard TEM!
- 1.8 nm for the highest-resolution labeling
- Ideal for Cryo-EM & protein subunit labeling
- Add our easy enhancement kits- for His-tag detection at ANY magnification!
- After labeling your sample, simply grow the gold labels in place
- Our easy, controllable enhancement kits enlarge the gold labelfor sharp, clear visibility in the light microscope, blots & gels!
Structure of NTA-Ni-Nanogold® 10 nm, showing the binding of the incorporated metal chelate to a His-tagged protein. Distance from the gold particle surface to the His tag is estimated to be 1.5 nm.
Check out all our His-tag detection kits:
10 nm Ni-NTA-Nanogold®
Optimum size for direct EM visualization
Use for post-embedding labeling
5 nm Ni-NTA-Nanogold®
Go straight to EM-
No silver / gold enhancement needed!
1.8 nm Ni-NTA-Nanogold®
Great for cryo-EM
Smallest probe: best penetration and highest resolution
10 nm & 5 nm Ni-NTA-Nanogold®
Perfect for direct EM visualization
Use for post-embedding labeling – No silver / gold enhancement needed!
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 5 & 10 nm gold nanoparticles are highly monodisperse and clearly visualized at TEM resolution in wider, cellular views –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: 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-Nanogold® 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.
- 5 nm Ni-NTA-Nanogold® is smaller than an unlabeled primary antibody, can more easily penetrate into specimens and access sterically restricted interior sites, and perturbs the ultrastructure less.
- In some systems these labels they both 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.
Structure of NTA-Ni(II)-5 / 10 nm Nanogold®, showing the binding of the incorporated metal chelate to a His-tagged protein. Distance from the gold particle surface to the His tag is estimated to be 1.5 nm.
Left: Ni NTA-Nanogold® clearly labels His-tags: Knob protein from adenovirus cloned with 6x-His tag, labeled with Ni-NTA-Nanogold, column purified from excess gold, and viewed in the scanning transmission electron microscope (STEM) unstained (Full width approximately 245 nm). Right: Near zero background with same protocol on sample without His-tags.
Transmission electron micrograph of 5 nm NTA Nanogold: average diameter 5.11±0.84nm.
1.8 nm Ni-NTA-Nanogold®
Great for cryo-EM
Smallest probe: best penetration and highest resolution
- Versatile: detects and localizes His-tagged recombinant proteins in electron microscope, light microscope and blots.
- Stable and soluble: surface functionalization and shell confer high stability combined with high solubility, making Ni-NTA-Nanogold® compatible with most systems.
- High resolution: 1.8 nm diameter gold particle provides high resolution for accurate, precise molecular and macromolecular identification and ultrastructural studies on isolated protein complexes and macromolecules.
- Permanent: stain does not fade.
Our original Ni-NTA-Nanogold® probe
Smallest size for maximum penetration!
Easily enhanced for any scope, cryo-EM, blots…
Try our precision nanoparticle developers for easily controlled development with low background!
Knob protein from adenovirus cloned with 6x-His tag, labeled with Ni-NTA-Nanogold, column purified from excess gold, and viewed in the scanning transmission electron microscope (STEM) unstained (Full width approximately 245 nm).
Structure of Ni-NTA-Nanogold® showing interaction with Interaction with a His-tagged protein
Applications
- Hybrid method to elucidate protein architecture with nanometer precision
Developed by Dr. Wei-hau Chang’s group (Chang, 2013)- Use our 3 different sizes of Ni-NTA-Nanogold® together in cryo-EM for better single particle analysis -5 & 10 nm are directly visible, without enhancement!
- Combine with FRET to further refine your protein map and observe conformational / postioning changes during interactions (Chang, 2013)
- Nickel staining His-tags for EM: High-resolution labeling of proteins, protein complexes or organelles containing recombinant His-tagged proteins for TEM or STEM localization.
- “Universal” pre-embedding labeling of His-tagged proteins in tissue sections for electron microscopic observation.
- Identifying His-tagged proteins in fractions during Ni-NTA-column purifications.
- Detection of recombinant His-tagged proteins on blots and in gels.
- Heavy atom labeling of regular structures for image analysis and structure solution.
- Gold Labeling of Protein Fusion Tags for EM
TEM projections of RNA polymerase II-TFIIF labeled with 5 nm Ni-NTA-Nanogold®: raw images in first row, filtered images in the second and the corresponding views of RNA polymerase II (Chang, 2013).