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 5 nm Amino Nanogold®.
- Carbohydrate labeling: use periodate or other mild, selective oxidants to oxidize carbohydrate sugars to aldehydes, then react with 5 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 5 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, 5 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®, 5 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.
- * 5 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 5 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, conjugates may be chromatographically separated by gel filtration. Alternatively, labeled proteins may be isolated by ammonium sulfate precipitation, and oligonucleotides by ethanol precipitation or gel electrophoresis. Ion exchange chromatography or hydrophobic interaction chromatography may also be useful. The maleimide group specifically reacts with a thiol under mild conditions to produce a stable, covalent thioether bond.
5 nm Nanogold® Labeling Reagents
The precision and versatility of Nanogold®, now in a larger 5 nm size
Like our smaller 1.4 nm Nanogold® reagents, it covalently reacts at specific sites under mild buffer conditions. This gives a well defined product that can be purified chromatographically or by ammonium sulfate precipitation.
Unlike conventional colloidal gold, 5 nm Nanogold® does not require any additional macromolecules for stabilization. Conjugate probes are smaller than colloidal gold probes and achieve higher resolution, more precise and more nearly quantitative labeling.
Make any molecule a gold probe
Nanogold® brings the versatility of fluorescent conjugation to gold labeling. Now you have a choice of sizes for Nanogold®: 0.8, 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
Unconjugated 5 nm Nanogold®, showing monodisperse, highly regular, spherically symmetrical 5 nm gold core and uniform, thin and consistent ligand coating. This ensures a highly regular particle size, smaller probe size, and reliable, reproducible labeling and EM results.
Easily enhanced for electron microscopy, light microscopy, cryo-EM, blots…
Try our precision nanoparticle developers for easily controlled development with low background!
Features and Advantages
- Stable, soluble and biocompatible: Designer coating gives solubility and biocompatibility for in vivo use. No residual charge means minimal non-specific binding.
- Highly monodisperse. Size variation less than 15% for 5 nm gold. 1.4, 5 and 12 nm Nanogold® enable up to triple labeling with non-overlapping sizes
- Molecular precision: 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: smaller probes penetrate better and label more densely.
- Easily enhanced. Silver or gold enhancement enlarges while retaining monodispersity – or affords super-sensitive detection for blots and optical systems.
- Pick the optimum size: smaller for high resolution, molecular labeling, larger for visualization on a cellular scale.
Although larger than our 1.4 nm Nanogold®, our new 5 nm Nanogold® is still relatively small in size, and highly uniform. Because it does not require additional proteins for stabilization, 5 nm Nanogold® conjugates are smaller than most conjugates prepared with conventional colloidal gold and uniform in overall size, giving them faster and more consistent penetration into specimens.
If larger particle sizes are needed, 5 nm Nanogold® may easily be enhanced with GoldEnhance™ gold enhancement reagents, or our HQ Silver™ or LI Silver™ silver enhancement reagents: Depending on the reagents used, a brief exposure (1 – 4 minutes) produce highly visible grains 10-20 nm in size for electron microscope identification, 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.