C1 Inhibitor is a multi-specific protease inhibitor present in human plasma and serum. Among the proteins it regulates are C1s and C1r of the C1 complement complex.

Purified human complement component C1q. Circulating C1q protein is a hexamer of three unique protein subunits (A,B, and C) with molecular weights of 29, 26 and 22 kD respectively.

Complement protein C1r is a serine protease that combines with C1q and C1s to form C1, the first component of the classical pathway of the complement system.

Complement protein C1s is a serine protease that combines with C1q and C1r to form C1, the first component of the classical pathway of the complement system. 

Complement protein C2, which is part of the classical pathway of the complement system, is cleaved by activated factor C1 into two fragments: C2b and C2a. C2a, a serine protease, then combines...

The complement pathway generates a C3 convertase, a serine protease that cleaves the central complement protein C3, and generates the major cleavage fragment C3b.

The complement pathway generates a C3 convertase, a serine protease that cleaves the central complement protein C3, and generates the major cleavage fragment C3b.

Human serum chemically depleted of C4 protein

Derived from proteolytic degradation of complement C4, C4a anaphylatoxin is a mediator of local inflammatory process.

C4b is a cleavage product of complement protein C4, along with C4a. C4b is a non-enzymatic component of the C3 and C5 convertases and thus essential for the propagation of the classical complement...

C5a, or C5 anaphylatoxin, is a mediator of local inflammatory process. It induces a variety of responses including intracellular calcium release, contraction of smooth muscle, increased vascular...

Purified human complement component C6.

A centrally important reaction that occurs during alternative pathway activation is the conversion of the Factor B zymogen to an active proteolytic enzyme. 

Human serum immunochemically depleted of Factor D protein. Quidel's depleted sera are specifically depleted of a single complement protein. With the exception of the depleted protein, the...

iC3b is generated during the activation of the complement system via the classical or alternative pathway. When a convertase enzyme cleaves C3, C3a and C3b are released in parallel.

Klotho, named after one of the Fates in Greek mythology, is a type-I transmembrane protein that is associated with many functions. A novel ß-glucuronidase, Klotho has been associated with...

Klotho, named after one of the Fates in Greek mythology, is a type-I transmembrane protein that is associated with many functions. A novel ß-glucuronidase, Klotho has been associated with...

A murine monoclonal antibody to an epitope in the C3d domain of C3

A murine monoclonal antibody to human C4d containing fragments

A murine monoclonal antibody to an epitope in the Bb fragment of Factor B

A murine monoclonal antibody to human Factor H

A murine monoclonal antibody to human Factor H

A rabbit antiserum raised against human complement C3a protein. C3a, along with C3b, is a cleavage product of complement protein C3. C3a is a anaphylatoxin that binds to the C3aR receptor.

A rabbit antiserum raised against human complement C4a protein. C4a is a protein fragment from the cleavage of complement protein C4, along with C4b.

A goat antiserum raised against human Factor D protein. Factor D is unique to the Alternative Complement Pathway. It consists of a single peptide chain with a molecular weight of 24 kD.

A goat antiserum raised against human complement Factor P protein.

A rabbit antiserum raised against human complement SC5b-9 protein. SC5b-9 is the soluble version of the terminal complement complex (TCC). The TCC is a multi-protein complex consisting of...

A rabbit antiserum raised against human complement Vitronectin protein.