Selectively label unique sugar or activated carboxyl sites
Positively ionizing amino- groups enable charge-based staining or labeling of negatively charged targets
- Carboxyl labeling: Label at carboxylic acid residues by converting the carboxylic acid to an activated form for reaction with 12 nm Amino Nanogold®.
- Carbohydrate labeling: use periodate or other mild, selective oxidants to oxidize carbohydrate sugars to aldehydes, then react with 12 nm Amino Nanogold® and reduce the resulting imides to give stable, amine-linked conjugates. See our Application note on RNA labeling for details.
- Protein labeling: activate 12 nm Amino Nanogold® using amine-reactive cross-linkers cross-link to a variety of other functional groupsor targets.
- Charge-based labeling: Under slightly acidic conditions, 12 nm Amino Nanogold® protonates and assumes a positive charge: use to label negatively ionizing regions in proteins or organelles.
- Make DNA nanowires: like the smaller 1.4 nm Positively Charged Nanogold®, 12 nm Amino Nanogold® can bind to the negatively charged groups in the DNA backbone; see our Microscopy & Microanlaysis 2001 paper for details. silver or gold enhance to make conductive nanowires.
- * 12 nm Amino Nanogold® is polyfunctional, so labeling reactions need to be planned to avoid cross-linking and control the ratio of Nanogold® to conjugate biomolecule. See the product information and instructions for more information and suggestions.
Use our unique Nanogold® labeling reagents just as you would use fluorescent labeling reagents.
Labeling with 12 nm Amino-Nanogold®, like the smaller 1.4 nm Amino-Nanogold®, is straightforward: reconstitute the 5 nm Amino Nanogold®, activate with the appropriate cross-linker, then incubate with the target molecule under suitable conditions.
Once reaction is complete, labeled proteins may be isolated by ammonium sulfate precipitation, and oligonucleotides by ethanol precipitation or gel electrophoresis. Alternatively, conjugates may be chromatographically separated by gel filtration; ion exchange chromatography or hydrophobic interaction chromatography may also be useful.
12 nm Nanogold® Labeling Reagents
Precise, permanent Nanogold® labeling reagents – Now in a larger size!
12 nm Nanogold® brings the power and versatility of Nanogold® in a even larger and more readily visualized 12 nm size. Like our smaller 5 nm and 1.4 nm Nanogold® reagents, it covalently reacts at specific sites under mild buffer conditions to give a well-defined product that may be purified chromatographically or by ammonium sulfate precipitation.
Unlike conventional colloidal gold, 12 nm Nanogold® does not require any additional macromolecules for stabilization. Conjugate probes are often smaller than colloidal gold probes and can achieve higher resolution because they can be prepares using smaller targeting agents, giving more precise and more nearly quantitative labeling.
Make any molecule a gold probe!
Unconjugated 12 nm Nanogold®, showing monodisperse, highly regular, spherically symmetrical 12 nm gold core and uniform, consistent ligand coating. This ensures a highly regular particle size and reliable, reproducible labeling and EM results.
Nanogold® brings the versatility of fluorescent conjugation to gold labeling.
Now you have a choice of sizes for Nanogold®: 1.4, 5 or 12 nm, enabling multiple labeling for electron microscopy without silver or gold enhancement!
- Antibodies
- Proteins
- Peptides
- Oligonucleotides and nucleosides: DNA, RNA and PNA
- Nanostructured materials
- Hormones
- Polymers
- Surfaces
Features and Advantages
- Stable, soluble and biocompatible. Designer coating gives solubility and biocompatibility so conjugates and probes may be used in vivo.
- Low background. No residual charge: minimal non-specific binding.
- Highly monodisperse. Size variation less than 10% for 12 nm. 1.4, 5 and 12 nm Nanogold enable double or even triple labeling with non-overlapping sizes
- Molecular precision. Use smaller targeting agents to make smaller primary probes that get the gold closer to the target.
- Site-specific conjugation enables programmed incorporation into nanostructured materials or components of self-assembling systems.
- No need for additional proteins or polymers: preparation is straightforward with no need for salt titration.
- Pick the optimum size: smaller for high resolution, molecular labeling, larger for visualization on a cellular scale.
- Easily enhanced. Enlarge with silver or gold enhancement and retain higher monodispersity – or achieve super-sensitive detection for blots and optical detection systems. If larger particle sizes are needed, 12 nm Nanogold® may easily be enhanced with:
Depending on the reagents used, a brief exposure (1 – 4 minutes) produces highly visible grains 20-30 nm in size for wide-field electron microscope visualization, while longer development times produce black signals, readily differentiated from organic chromogens, that are easily seen in the light microscope and on immunoblots, gels and Western blots.