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Gold Conjugates

Trusted Gold Conjugates from BBI

All of our conjugates are manufactured using our unique gold nanoparticles. We use our long-established proven processes to manufacture conjugates with outstanding performance and long-term stability. Our catalogue gold conjugates offer optimal performance, cost effectiveness and guaranteed quality, and are designed to help you develop and manufacture your assay rapidly and efficiently. 

We manufacture all of our conjugates under our ISO13485 certification at our Crumlin headquarters. 

BBI Solutions gold conjugates for lateral flow 

Our catalogue range includes the following conjugates: 

Anti-Biotin 

Anti-Human 

Control line 

Anti-species 

Fertility 

Monoclonal anti Biotin 40nm 

Goat anti Human IgG (H+L) 40nm 

Chicken IgY 40nm 

Goat anti Rabbit 40nm 

Human Chorionic Gonadtrophin (HCG) 40nm 

Goat anti Biotin 40nm 

Goat anti Human IgG 40nm 

Mouse IgG 40nm 

Goat anti Mouse IgG (H+L) 40nm 

Human Lutienizing Hormone (LH) 40nm 

 

Goat anti Human IgM 40nm 

Bovine Serum Albumin 40nm * 

 

 

 

Goat anti Human IgA 40nm 

Goat anti Mouse IgG (H+L) 40nm 

 

 

 

Protein A 40nm 

Goat anti Rabbit 40nm 

 

 

*Negative control conjugate 

Pease note: If you are based outside of the EU there will be a 5 day lead time added to your order to enable us to comply with the Animal and Plant Health Agency (APHA) export/import policy. 

  • All of our conjugates are supplied at OD10 and are available as a 5ml sample, 100ml and 500ml pack sizes 
  • If you are looking for a conjugate which is not in our standard product range, or for an existing conjugate to be supplied at a different OD, learn more about our custom conjugation service here < add link> or contact us with your requirements. 

BBI Solutions Gold Conjugates for Microscopy 

Gold labels offer an effective method of labelling antigens for visualisation in the electron microscope.  

BBI has a range of EM grade conjugates that combine different antibodies on a range of particles, predominantly from 5, 10 and 15nm. For researchers beginning to work with immunogold labelling, we recommend 10nm gold conjugates for observation, at a range of magnifications. 

The main advantages of gold labelling lie in the high contrast and unequivocal nature of the label, the range of particle sizes suitable for different magnifications, the extreme sensitivity and the stability of the signal. 

Please contact our Customer Services Team directly to discuss your requirements on tel:+44 (0) 1495 363000 or alternatively you can submit an enquiry here.

 

  

 

 

Related Products

If you require any further product specific technical information or datasheets please submit your request to our technical team here 

Gold Conjugates FAQs

Our team are here to help! If you can’t find the answer you are looking for please contact us

The antibodies are passively conjugated to the gold nanoparticle surface (no covalent or linker chemistry is used). Protein binds to gold colloid through amino acid residues: charge attraction (lysine), hydrophobic attraction (tryptophan), and sulphur bonding (cysteine).

IgG is the most popular isotype for conjugation and can be conjugated with a high success rate. The antibody binds to the gold nanoparticles through the Fc region, leaving the Fab region exposed and able to bind the antigen of interest. IgG3 antibodies are more difficult to work with so these should
be avoided if possible.

IgM conjugations have a lower success rate. Cross-linking can occur when they are conjugated, and the Fc regions cannot always be exposed without damaging the integrity of the antibody.

IgE antibodies are raised in an allergic response, these antibodies can be conjugated to gold nanoparticles.

IgY antibodies are functionally similar to IgG antibodies and these can be conjugated to gold nanoparticles with a high success rate. Antigen conjugations are possible, although the success rate is lower. BBI can also conjugate antibody fragments- Fab, Fc, ScFv and limited experience with nanobodies.

The majority of gold conjugates (BA Grade and Custom Conjugates) are presented in a low molarity Borax buffer. EM grade conjugates are presented in a Tris-buffer saline solution containing 30% glycerol.

EM Grade gold conjugates can be frozen for long term storage and thawed for usage as these conjugates contain glycerol in their final buffer.

BA Grade and Custom conjugates cannot be frozen. Freezing of these products will cause the gold nanoparticles to completely and irreversibly aggregate and should be avoided.

It is recommended to store the gold conjugates (BA Grade and Custom Conjugates) at 2-8°C. EM Grade conjugates can be kept frozen at -20°C for long term storage.

BA refers to BioAssay. These conjugates are stock products which are routinely manufactured at BBI Solutions. These are most commonly used in lateral flow diagnostic tests. The particle size is 40nm.

CC refers to custom conjugates. These conjugates are similar to BA Grade conjugates but are usually manufactured on a custom basis by request of a customer. The particle size most
commonly used is 40nm.

EM refers to Electron Microscopy. These conjugates are different to BA and CC conjugates, are usually made with smaller nanoparticles and are most often used in electron microscopy. The particle size most commonly used is 10nm.

In BBIs experience, 40nm is the preferred particle size. 40nm provides good signal visibility whilst encountering relatively little steric hindrance.

The gold nanoparticles are well dispersed. The conjugate is tested under the Transmission Electron Microscope (TEM) and a specification that ≥85% particles are singlets with no clusters > 10 is applied (except for BA Grade Protein A conjugates where a specification that ≥90% particles are singlets is
applied).

EM Grade conjugates are available in 0.25ml and 1ml pack sizes.

BA Grade conjugates are available in 5ml, 100ml and 500ml pack sizes. 5ml will be for samples only.

Custom conjugates are available in any pack size. Minimum order volume is usually 5ml. For orders >500ml, individual pack sizes do not exceed 500ml.

The expiry date is stated on the label of each batch. In general BA Grade conjugates have a shelf life of 2 years from the point of manufacture when stored at 2-8°C. BA.GAM40 stability studies are ongoing- this is currently not supplied with an expiry date.

No expiry date is applied to EM Grade conjugates. Anecdotally, these have been used 5+ years after the date of manufacture with no loss of functionality.

No expiry date is applied to Custom Conjugates, unless at request of the customer. A cost would apply for the panel of work required to assign an expiry date.

The gold conjugates are manufactured at our ISO 13485:2015 certified facility in Crumlin, South Wales, UK.

Your inputs, following discussion of your application with our team,

▪ Selected detector protein (antibody/protein). Supplied by customer or BBI can source and recharge the customer.
▪ Identify target sensitivity
▪ Identify particle size
▪ Concentration of final conjugate required
▪ Provide 3-5mg of protein for conjugation and QC materials (capture, target antigen). Antigen no
more than Cat II Biohazard level

BBI outputs

▪ Initial 5-10ml of final conjugate – (enough for 1000 prototype lateral flow strips*)*using a 1:5
dilution of OD10 conjugate per strip
▪ Excess reagents banked for future production
▪ Full laboratory report on performance customised to your requirements
▪ Access to technical team post conjugation

Gold Conjugation- why quality gold matters 

One of the most important factors in the development of a reliable assay is the quality of the gold conjugate. At BBI Solutions, we use the highest quality grades of gold nanoparticles and apply our unique conjugation protocol to deliver an optimised product that meets the demands of your assay. 

Whether you are looking to bind gold to a specific antibody and need a custom conjugation, or off the shelf products, BBI can help and deliver. 

Custom conjugation service from BBI Solutions 

Our custom conjugation service allows us to develop high-quality conjugates using reagents provided by you or sourced by us. 

Our service includes: 

Advice on the optimum nanoparticle and size to use for your application 

Conjugation of your antibody or protein to a nanoparticle and size of your choice 

Particle Analysis 

Batch sizes up to 24L at OD10 

Sourcing your required antibody or protein 

Long term stability analysis (on request) 

Selection of appropriate final buffer for the conjugate 

Custom OD preparation (not limited to OD10) 

Antibody Screening 

QC test development 

Optimisation of sensitivity and potential stability 

Comprehensive lab report on conjugate performance 

  

Designed to meet your individual needs 

Specificity, sensitivity and reproducibility should define the specification and fulfil your absolute minimum expectations of the conjugate. 

Our scientists work in partnership with customers to bring all the vital ingredients together and provide sensitive, stable, reproducible conjugates time after time. 

At the start of the project we will ask you for the following customer inputs and deliver the listed outputs: 

 

Customer inputs 

BBI outputs 

Choose your target protein (antibody/protein) 

Initial 10ml of final optimised product – (enough for 1000 prototype lateral flow strips*) 

Identify target sensitivity 

Excess reagents banked for future production 

Identify particle size 

Full laboratory report on performance customised to your requirements 

Concentration of final conjugate required 

Access to technical team post conjugation 

Provide 3-5mg of protein for conjugation and QC materials 

*using a 1:5 dilution of OD10 conjugate per strip 

  

A quality solution 

Every custom conjugation is QC tested with customer supplied materials. Your unique sign-off procedure is brought into BBI to ensure every batch of gold we deliver meets your requirements and works with your in-house system. 

Bulk production 

Following collaboration on the optimisation of the conjugate to test specifications, we are able to provide conjugate in bulk. We can put a commercial supply plan in place and supply single batch volumes of up to 24l at OD10, delivered on a two-week turnaround. 

To find out more about our conjugation service, contact us » 

Off the shelf conjugates 

For optimal performance, cost effectiveness and guaranteed quality, we offer off the shelf catalogue gold conjugates, designed to help you develop and manufacture your assay at a rapid and economical rate. 

Our catalogue range includes: 

  • Anti-biotin  
  • Anti-human 
  • Control line 
  • Anti-species 
  • Disease state conjugates  
  • Fertility conjugates 

All conjugates are manufactured using our unique gold nanoparticles, providing outstanding performance and long term stability. 

If you are looking for a conjugate which is not in our standard product range, please contact us with your requirements. 

 

Anti-Biotin 

Anti-Human 

Control line 

Anti-species 

Fertility 

Monoclonal anti Biotin 40nm 

Goat anti Human IgG (H+L) 40nm 

Chicken IgY 40nm 

Goat anti Rabbit 40nm 

Human Chorionic Gonadtrophin (HCG) 40nm 

Goat anti Biotin 40nm 

Goat anti Human IgG 40nm 

Mouse IgG 40nm 

Goat anti Mouse IgG (H+L) 40nm 

Human Lutienizing Hormone (LH) 40nm 

 

Goat anti Human IgM 40nm 

Bovine Serum Albumin 40nm * 

 

 

 

Goat anti Human IgA 40nm 

Goat anti Mouse IgG (H+L) 40nm 

 

 

 

Protein A 40nm 

Goat anti Rabbit 40nm 

 

 

*Negative control conjugate 

Gold Conjugates for Microscopy 

Gold labels offer an effective method of labelling antigens for visualisation in the electron microscope. BBI has a range of EM grade conjugates that combine different antibodies on a range of particles, predominantly  2, 5, 10, 15, 20, 30 & 40nm. For researchers beginning to work with immunogold labelling, we recommend 10nm gold conjugates for observation, at a range of magnifications. 

The main advantages of gold labelling lie in the high contrast and unequivocal nature of the label, the range of particle sizes suitable for different magnifications, the extreme sensitivity and the stability of the signal. 

Our technical team are available to discuss which conjugate is right for your application or to answer your nanoparticle based questions. LINK HERE

Applications 

BBI Solutions’ gold nanoparticles are renowned for their use in lateral flow tests; however, the use of nanoparticles ranges from health and material technology to the environment and energy sectors. 

The technology sectors and applications listed below provide a summary of where our gold nanoparticles are being used by our customers and partners: 

Size range of nanoparticles 

Area of use 

Function 

Small (2nm -15nm) 

Immunohistochemistry 
Light Microscopy 
High magnification TEM 
Biomarkers 
High throughput microarray platforms 

Antibody/antigen detection in cells 
Detection of biomarkers in cells for imaging and sensing 
Blood typing 
SDS screening 

Medium (20nm – 80nm) 

Lateral flow assays 
TEM and SEM 
Biomarkers 
SERS 
DNA detection 

Detection of food borne pathogens 
Bacteria in blood 
Drugs of abuse 
Clinical biomarkers 
Veterinary biomarkers 
Mycotoxin detection 

Large (80nm – 250nm) 

Flow cytometry 
SERS 
Forensic science 

Detection of CD4 cells using flow cytometry 
Clinical biomarker detection using Raman spectroscopy 

 
 

 

Technical Documents

If you require any further product specific technical information or datasheets please submit your request to our technical team here 

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BBI Solutions Brands

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The acquisition of DIARECT in June 2020 and their world leading recombinant autoimmune antigen capability immediately enhances BBI’s portfolio and position as a ‘complete’ immunoassay reagent supplier. This further enhances BBI’s position as the world’s largest diagnostics components company with a market leading antigen portfolio.

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Maine Biotechnology Services brings 27 years of knowledge, experience, process development, and project management to our customers to ensure the best possible antibodies for any application. As antibody development goals in the biotechnology and pharmaceutical industry have evolved the acquisition of MBS will help BBI further meet and exceed our customers needs.

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