Protein G Gold Conjugate (20nm, 10 OD) (ab270602) is an aqueous suspension of 20 nm gold nanoparticles covalently bound with Protein G forming a highly stable conjugate.
- Binds with high affinity to IgG subtypes
- Proprietary surface coating shields the metallic core of the nanoparticle from the external environment, eliminating colloidal instability
- Consistent high quality and batch-to-batch reproducibility
- Available in different formats to fit your experimental needs
View Alternative Names
IgG-binding protein G, Immunoglobulin G binding protein G [Precursor], SPG2_STRSG, spg, spg immunoglobulin G-binding protein
Product details
Protein G Gold Conjugate (20nm, 10 OD) (ab270602) is manufactured using our Gold Nanoparticles which have a protective coating that can withstand the most extreme conditions (e.g. 2.5 M NaOH at 70°C for >1 hour). The irreversible covalent attachment does not allow the desorption of the Protein A, which is a major problem associated with gold conjugates when developed using passive adsorption techniques.
To exchange the conjugate into a specific buffer for your assay or test, centrifuge the conjugate in a microfuge at 9,000 x g for 20 minutes. Carefully remove the supernatant and add your preferred buffer. It is important to avoid substances that have a very high affinity for gold (e.g. thiols).
The maximum absorbance for Protein G Gold Conjugate (20nm, 10 OD) is at 528 nm. To determine the effective concentration of the conjugate obtained we advise to measure the Absmax of light using an UV-vis spectrophotometer after diluting your sample to an appropriate range for your piece of equipment (e.g. if a 40 nm gold conjugate is at 10 OD and is diluted 1:10 the Abs530nm for a 1 cm light path is expected to be around 1 AU).
Before using Protein G Gold Conjugate (20nm, 10 OD) to detect a specific antibody we recommend that you check the affinity of Protein A for that antibody and subtype (see table below). Rabbit and human IgGs, for example, are good candidates because they bind to Protein A with high affinity.
| Species | IgG | Binding strength |
| Rabbit | IgG | High |
| Human | IgG | High |
| Mouse | IgG1 | Medium |
| Mouse | IgG2a | High |
| Mouse | IgG2b | Medium |
| Mouse | IgG3 | Medium |
| Mouse | IgM | No binding |
| Goat | IgG | High |
| Sheep | IgG | High |
| Rat | IgG1 | Weak/Medium |
| Rat | IgG2a | High |
| Rat | IgG2b | Weak/Medium |
| Rat | IgG2c | Weak/Medium |
Protein G Gold Conjugate (20nm, 10 OD) is tested as a detector tool in Lateral Flow Assay but can also be used in electron and light microscopy, immunoblotting, and dot-blot. As Protein G Gold Conjugate (20nm, 10 OD) affinity for antibodies can vary, a titration of the specific antibody used is recommended in order to obtain the optimal performance. We recommend performing the incubation of Protein G Gold Conjugate (20nm, 10 OD) with the antibody in a buffer that has a pH between 5 and 7.5 for at least 10-15 minutes. After this stage do not centrifuge the gold complex.
This product is manufactured by Expedeon, an Abcam company. It was previously called 20nm InnovaCoat® GOLD (10 OD) Protein G Conjugate. Expedeon product code 225-0200 is the same as the 200 μl size of this product and code 225-1000 is the same as the 1 mL size.
Properties and storage information
Shipped at conditions
Appropriate short-term storage conditions
Appropriate long-term storage conditions
Specifications
Form
Liquid
General info
Target data
Complementary Products
Product promise
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