Home \ Antibodies \ C3b/iC3b, Human, mAb 5G9
Catalog # HM2285

C3b/iC3b, Human, mAb 5G9

The monoclonal antibody 5G9 recognizes Complement Factor C3b/iC3b, it specifically binds human C3 as well as the breakdown products C3b and iC3b.

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The Vital Role of C3b/iC3b in Complement System Activation

C3 plays a pivotal role in activating the complement system, a key component of our immune response. This activation is crucial for both the classical and alternative complement pathways. A deficiency in C3 can increase susceptibility to bacterial infections, underlining the importance of understanding the C3b/iC3b dynamic.

C3 Convertases: The Pathway to C3b/iC3b Formation

One form of C3 convertase, C4b2a, is vital in the classical and lectin pathways. It catalyzes the cleavage of C3 into C3a and C3b. While C3a functions as an anaphylotoxin and cytokine precursor like ASP, C3b acts as an opsonizing agent. The transformation of C3b into C3c and C3d, facilitated by Factor I, plays a crucial role in enhancing B cell responses. In the alternative pathway, C3b is also generated by C3bBb, another form of C3 convertase, leading to the creation of the C3b/iC3b forms.

Mechanics of C3b/iC3b in Immune Regulation

Once formed, C3b can bind to surfaces via a reactive thioester, a crucial step in the complement activation process. The alternative pathway’s C3 convertase, C3bBb, undergoes deactivation in several steps. Initially, the Bb component is removed by proteins with decay-accelerating factor activity. Subsequently, C3b is methodically broken down to iC3b, then to C3c and C3dg, and finally to C3d. This process, involving Factor I and CR1 as a cofactor, is pivotal in the regulation of the complement system.

Clinical Relevance of C3b/iC3b Levels in Diagnosis

Monitoring levels of C3, and by extension C3b/iC3b, in the blood can provide valuable diagnostic insights. For example, low levels of C3 are linked with certain kidney diseases such as post-infectious glomerulonephritis and shunt nephritis. Understanding the behavior and levels of C3b/iC3b is thus critical in both the diagnosis and potential treatment of various medical conditions.

Not sure which C3 antibody to use?

With numerous options available, it is essential to select the right C3 antibody to ensure the success of your research. We designed a guide to assist you in making an informed decision:

Go to our C3 researcher’s guide and choose the right antibody

Functional studies

Application Notes
mAb 5G9 inhibits the classical pathway and not the alternative pathway (Ref1).

The typical starting working dilution is 1:50. For functional studies, in vitro dilutions have to be optimized in user’s experimental setting.

Product type
Monoclonal antibodies
1 mg, 10 mg, 100 µg, 20 µg, 5 mg, 500 µg
Quantities >500 µg will be send without preservative and carrier free. Quantities <500 µg will be send with preservative and carrier. exact formulation can be found on the datasheet.
Mouse IgG2a
Storage and stability
Product should be stored at 4°C. Under recommended storage conditions, product is stable for at least one year. The exact expiry date is indicated on the label.
For research use only. Not for use in or on humans or animals or for diagnostics. It is the responsibility of the user to comply with all local/state and federal rules in the use of this product. Hycult Biotech is not responsible for any patent infringements that might result from the use or derivation of this product.
Infectious diseases, Nephrology

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