Nanogold particles is a 1.4 nm diameter gold compound which can be covalently and specifically linked to an antibody or to a hinge thiol on Fab' or IgG. These substantially smaller antibody-Nanogold probes reach more antigens and provide better labeling and stability compared to colloidal gold preparation. They can be viewed directly in TEM without silver enhancement or developed with silver to any appropriate size
for enhanced visibility with other counter stains.
Bio-Synthesis can custom conjugate 1.4 nm Nanogold-antibody conjugates using your own primary antibody (lgG or Fab'), proteins, peptides, lectins, and other molecules.Contact us with your specific needs.
Features of Nanogold Antibody Conjugates
- Excellent stability compared to colloidal gold -antibody preparation
- Smallest commercially available gold immunoprobes
- Unparalleled penetration of conjugates up to 40µm
- Extremely uniform 1.4nm diameter gold label
- Close to one Nanogold® particle to one Fab' (or IgG)
- Low non-specific affinity gives minimal background
- Ultrasensitivity with silver enhancement: 0.1pg of antigen detection on immunoblots
- Label at specific sites which do not obstruct antigen binding region
- High stability and long shelf life
- Conjugates are stable with wide ranges of pH and ionic strengths
Conjugation Chemistries
Standard immobilization of antibodies using modified/activated or native solid supports. Malemide activated nanogold can be used with a variety of homo- or heterobifunctional crosslinkers, or directly labeled with RNA or glycoprotein selectively through thiols or modified sulfo-NHS-Nanogold with primary aliphatic amines (N-terminal or lysine residues).
Quality Control Criteria
The custom prepared product is quality controlled by Bio-Synthesis according to our in-house standards with respect to size distribution and clustering. In agreement with the principal investigator, the binding substance's specific quality control criteria are determined. The quality control criteria are tailored for each individual assignment. The custom conjugate is approved only when both sets of quality control criteria have been met.
Custom Formulation
Our conjugation is based on a mixed short length polymer cross linked covalent bonded technique. We require ligands with either a primary amine or that are biotinylated.
Prices
Due to the nature of each project, a written quotation will be made stating the cost and time required after receipt of the antibody sample.
Delivery
Labeled products will be supplied as 1 ml, containing 80 µg of labeled antibody.
Products will be shipped in 20 mM sodium phosphate solution, pH 7.4, with 150 mM sodium chloride, 0.1% bovine serum albumin and 0.05% sodium azide as preservative(expiration date 12 months from packing), unless you specify otherwise. For example,conjugates may be supplied without bovine serum albumin. Custom labeled conjugates can be supplied in the 1 mL size only; we cannot accept orders for smaller sizes.
Conjugation is guaranteed and based on dynamic light scattering (DLS) results for both size and charge. Surface coverage, reactivity, and activity of the conjugation are unmeasured. Conjugations take 1-2 weeks. All shipments are sent Fed Ex Standard Overnight for domestic delivery.
No shipments on Fridays.
Sample Submission Guideline
As a rule, Bio-Synthesis will only accept pure substances as starting material,either lyophilized or dissolved in a medium of known chemical composition. Interfering substances must not be present. Non-commercial antibodies supplied by the customer
should be affinity purified. Please provide gel electrophoresis data along with your antibody. Commercially available antibodies can be supplied by customers or ordered through Bio-Synthesis. We can assist in antibody modification or fragmentation prior to any immobilization reaction.
Antibody Supplied by Customers
We can also custom label your monoclonal IgG molecules or prepare labeled Fab'fragments. Fab' fragments can be labeled if they are supplied as F(ab')2 fragments. Where IgG is supplied, labeled Fab' fragments can be produced only for the IgG1 and IgG2a subclasses, not from IgG2b or IgG3 monoclonal antibodies. We recommend using our labeling reagents, monomaleimido Nanogold® and monomaleimido undecagold. Before placing a custom synthesis order, these reagents will label antibodies using the same reaction in the same manner as preparing catalog conjugates.
Amount of Antibody Required:
- For labeling of IgG molecules: 500 µg of antibody is required.
- For preparation of labeled Fab' fragments room F(ab')2 fragments: 500 mg of F(ab')2 fragments is required.
- For preparation of labeled Fab' fragments from IgG molecules: 2 mg of IgG is required.
The following data is particularly useful:
Molecular Weight
All of our labeling reactions use specific molar ratios of gold to probe. We need the molecular weight to calculate how much gold labeling reagent we will need, how much of the probe we will need to use for labeling, and also which product isolation protocol to use.
Optical Density or UV/visible Absorption Data
The extinction coefficients of undecagold, Nanogold® and FluoroNanogold at specific wavelengths have been accurately determined, and these values allow us to determine
how successfully your probe has been labeled. If you supply or refer us to specific values for your probe, we can provide you with the exact ratio of gold cluster label to probe in the product.
Molecular structure and functional groups
Ideally, targeted biomolecules should be labeled at a unique reactive group, remote from the substrate binding region. Bio-Synthesis tries to identify suitable sites for labeling,such as a unique thiol or a terminal primary amine. Some idea of the overall structure of your molecule and which regions are thought to bind to the target would be very helpful in selecting a labeling site. Thiols, primary amines, carboxylates and aldehydes may all be labeled. Labeling through hydroxyls or cis-1,2-dihydroxy groups is also possible; other groups may require extensive synthetic modifications which will increase the cost and synthesis time considerably.
References for labeling with other tags
We can often obtain a good idea about which labeling approaches might work from related literature articles. A paper which describes a successful labeling with a fluorophore, for example, is a good starting point for evaluating potential gold-labeling strategies. Our gold labels are conjugated using similar cross-linking reactions and have similar site requirements. Data on properties such as solubility and compatibility with various solvents are also useful, because small molecules can sometimes alter
the solubility properties of gold clusters significantly. Knowing an alternative solvent beforehand avoids solubility testing later.
The use of the highest quality immunogold conjugates is essential to the quality
of your assay. Bio-Synthesis offers custom colloidal gold conjugation services to a wide variety of molecules and proteins.Colloidal gold is available for all particle sizes from 5-40 nanometers. Conjugations take approximately 1-2 weeks. Please specify the quantity of material and size of the particles prior to placing an order so that we may price appropriately.The yield is not determined until after conjugation is complete and cannot be estimated prior to conjugation.
Features of Nanogold Antibody Conjugates
- Wide range of particle size
- No aggregation
- Conjugation of single protein to gold colloid
- Bulk supply
- Uniform in size
Conjugation Chemistries
Standard immobilization of antibodies using modified/activated or native solid supports,maleimide activated nanogold can be used with a variety of homo- or heterobifunctional crosslinkers, or directly labeled with RNA or glycoprotein selectively through thiols or modified sulfo-NHS-colloidal gold with primary aliphatic amines (N-terminal or lysine residues).
Quality Control Criteria
The custom prepared products are quality controlled by Bio-Synthesis according to our in-house standards, with respect to size distribution and clustering. In agreement with the principal investigator, the binding substance's specific quality control criteria are determined. These are tailored for each individual assignment. The custom conjugate is approved only when both sets of quality control criteria have been met.
Custom Formulation
Our conjugation is based on a mixed short length polymer cross linked covalent bonded technique. We require ligands with either a primary amine or that are biotinylated.
Prices
Due to the nature of each project, a written quotation will be made stating the cost and time required after the receipt of the antibody sample.
Delivery
Labeled products will be supplied as 1 ml, containing 80 µg of labeled antibody.Products will be shipped in 20 mM sodium phosphate solution, pH 7.4, with 150 mM sodium chloride, 0.1% bovine serum albumin and 0.05% sodium azide as preservative(Expiration date 12 months from packing), unless you specify otherwise. For example,
conjugates may be supplied without bovine serum albumin. Custom labeled conjugates can be supplied in the 1 mL size only; we cannot accept orders for smaller sizes.
This conjugation is guaranteed and based on dynamic light scattering (DLS) results for both size and charge. Surface coverage, reactivity, and activity of the conjugation is unmeasured. Conjugations take 1-2 weeks. All shipments are sent Fed Ex Standard Overnight for domestic delivery. *No shipments on Fridays
Sample Submission Guideline
As a rule, Bio-Synthesis will only accept pure substances as starting material,either lyophilized or dissolved in a medium of known chemical composition. Interfering substances must not be present. Non-commercial antibodies supplied by the customer should be affinity purified. Please provide gel electrophoresis data along with
your antibody. Commercially available antibodies can be supplied by customers or ordered through Bio-Synthesis. We can assist in antibody modification or fragmentation prior to any immobilization reaction.
Antibodies for Flow Cytometry
Bio-Synthesis offers custom conjugation of nanocrystals or Qdot to a wide variety of molecules: proteins, DNA or other molecules provided by our client or sourced by BSI. Conjugations take approximately 1-2 weeks. Please specify the quantity of material prior to placing an order, so that we may set an appropriate price. The ratio of protein to nanocrystals will be based on the customer's requirements.
Nanocrystal Conjugation Service Features
- Hydrodynamic size before and after conjugation
- Fluorescent emission quantum efficiency
- Electrophoresis gel to identify conjugates
- Emission wavelength
- 4 nmoles QDs, 1 mg iron oxide and 1 mg Au or Ag nanocrystals.
About Nanocrystals
Nanocrystals are nanometer-scale, high quantum yield semiconductor particles with unique fluorescent properties that differ from those of typical dye molecules. Their heavy metal core particle is surrounded by a patented surface coating, enabling attachment to antibodies, proteins, oligonucleotides, and other biomolecules, which can be directly used as detection probes. The nanocrystals exhibit intrinsically bright color and are exceptionally photostable. The nanocrystals have a narrow emission spectra, which reduces background staining. Nanocrystals are also often used as simple replacements for analogous conventional dye conjugates when their unique performance characteristics are required
to achieve optimal results in applications used in immunocytochemistry, immunohistochemistry
or flow cytometry.
The large source area of the nanocrystal allows simultaneous conjugation of many biomolecules to a single crystal. Nanocrystal conjugates are also easy to use in multicolor applications. They are compatible with other nanocrystals and traditional dyes and, since they are named after their emission wavelength, it is easy to select
the right fluorophore for staining panels.
Benefits of Nanocrystal Conjugates Over Conventional Dyes Are :
Flexibility - Suitable for both monoclonal and purified polyclonal
antibody conjugation, other proteins (MW between 30-150 kDa), and nucleic acids.
Narrow, Symmetrical Emission Spectra - Narrow emission spectra
allow less overlap between dyes, reducing the amount of complex compensation calculation to obtain final data.
Bright Staining Intensity - High signal to noise ratio means you are seeing your sample and not artifacts.
Superior Photostability - Nanocrystal conjugates remain fluorescent
under constant illumination, while conventional dyes photobleach to varying degrees.
Multicolor Usage - Fully compatible with all nanocrystals and conventional
dyes, expanding your color options in multicolor staining panels.
Conjugation Chemistries
Protein, antibody, peptide or oligonucleotide can be conjugated to nanocrystals using
standard conjugation chemistry by converting the surface group of a nanocrystal,
such as carboxyl (-COOH), amino (-NH2), hydroxyl (OH) and alkyl to a functional
group using various type of homo- or heterobifunctional crosslinkers and buffer solutions.
Quality Control Criteria
The custom prepared products are quality controlled by Bio-Synthesis according to our in-house standards. One example is the electrophoresis gel and also the change of both the particle size and zeta potential of the nanocrystals before and after
conjugation. Hydrodynamic size, TOC analysis or Emission quantum efficiency.
Prices
Due to the nature of each project, a written quotation will be made stating the cost and time required after receipt of the antibody sample.
Delivery
Conjugations take 1-2 weeks. All shipments are sent Fed Ex Standard Overnight for domestic delivery.
*No shipments on Fridays
Sample Submission Guideline
As a rule, Bio-Synthesis will only accept pure substances as starting material, either lyophilized or dissolved in a medium of known chemical composition. Interfering substances must not be present. Non-commercial antibodies supplied by the customer should be affinity purified. Please provide gel electrophoresis data along with
your antibody. Commercially available antibodies can be supplied by customers or ordered through Bio-Synthesis. We can assist in antibody modification or fragmentation prior to any immobilization reaction.