• 45-1 Ramsey Road, Shirley, NY 11967, USA
  • 1-631-466-5530

Complement Function/Activity Test

Complement function or activity test allows for the determination of whether the protein is present and whether it has normal functional activity. A wide range of assays are now available in Creative Biolabs, such as Hemolysis assays (CH50 or AH50), Elisa Assays (c3a, c5a, FH, FB, C5b-9 or others), Complement Inhibitor Validation (IC50)......

Explore the collection of assays

Creative Biolabs provides advanced complement therapeutic and drug discovery services of C3-target of complement system for our customs based on the years of research in this field. We are confident to offer high-ranking technologies and cost-effective service to assist our clients’ project.

Complement System

The complement system is considered an ancient and evolutionary conserved component of the innate immune mechanism. It comprises more than 30 element proteins, regulators and receptors which collaborate to form the complement cascade defending against infections as well as clearing invaders. There is an increasing appreciation that the complement system involves numerous physiological and pathological processes in the body.


Three major pathways of complement which are the classical, alternative and lectin pathways converge on complement C3. As the central component among the intricate protein network of the complement system, C3 is associated with diverse immunomodulatory system and biological process that affect human physiology and pathophysiology, thereby representing a ‘hot-spot’ for current complement-targeted therapeutic intervention. It is the most abundant complement protein which mediates numerous protective effects or pathological effects of complement. C3 plays roles in complement cascade by active fragments or complexes, which are achieved through a panel of enzyme processing procedure.

C4b2a is C3 convertase (C3-cleaving enzyme) that triggers the activation in classical (antibody) or lectin (sugar) pathways, whereas in the alternative pathway that is C3bBb. Active fragments or complexes of complement proteins are produced for corresponding activities through the effect of C3 convertases. C3 fragments like C3b, C3dg, and iC3b can covalently bind to their targets recruiting phagocytes to the targets and performing phagocytosis. In addition, they facilitate the activation of B cells for enhancing humoral immunity. The smaller fragment C3a can strengthen the antigen presenting cells (APCs) to present antigens and stimulate T cell proliferation. Downstream of C3, the membrane attack complex (MAC) forms ultimately with the help of C5 convertase and other important factors to lyse the target bacteria and activating cells.

The complement pathway.

Fig.1 The complement pathway. (Trouw, 2017)

C3 Related Disease

As we all know, the complement cascade would never be an isolated system but critically intertwined with other systems such as immune, inflammatory system, and related to other significant developmental or metabolic processes. While the underlying processes within the cascade during complement activation are highly complex and diverse, this level of complexity is not only essential for an adequate response to distinct triggers but also offers a wide panel of potential targets for therapeutic intervention. In addition, with the fact that the mechanisms of numerous complement-related disorders are revealed in recent years, the role of complement is undergoing a profound paradigm shift and therapeutic intervention is becoming increasingly prevalent.

Based on a thorough understanding of the complement system as well as abundant research experience of complement therapeutic, Creative Biolabs has developed the C3-target complement therapeutic services for various conditions which including but not limited to:

  1. Systemic lupus erythematosus
  2. Endotoxin shock
  3. Membranoproliferative glomerulonephritis

It is of great honor for us to share these experiences with our clients and give a hand in the research of therapeutic intervention. If you are interested in our service, please feel free to contact us for more information and a detailed quote.

1. Trouw, L. A. et al. The complement system as a potential therapeutic target in rheumatic disease. Nature Reviews Rheumatology. 2017, 13(9): 538.

For lab research use only.

Online Inquiry

  • Verification code
    Click image to refresh the verification code.

Contact us


  • Tel: 1-631-466-5530
  • Fax: 1-631-207-8356
  • Email:
  • 45-1 Ramsey Road, Shirley, NY 11967, USA
  • Global Locations

Follow us on

Complement System
Copyright © 2007 - 2021 Creative Biolabs. All Rights Reserved.