Complement Function/Activity Test

Background

Creative Biolabs is a leading diagnostic service company with a robust and standardized complement assay platform, supporting pre-clinical research in complement field. We offer a full range of complement function or activity test services and use high-quality standards in all operations, including the testing procedures and delivery reports. Our specialized and dedicated team is available to support our clients with R&D, pre-clinical development programs.

Why Do Test for Complement Function or Activity?

Complement function or activity tests are developed to find patients suffering from complement deficiency. Deficiencies in complement components and their regulatory molecules have been reported in a variety of diseases, such as recurrent infections, autoimmune and renal diseases. Today, these tests are also widely used for drug development of new complement-targeted drugs. Therefore, functional or activity tests are of great importance to screen complement defects and complement-targeted drug development.

Services Overview

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. In general, the measurement of the function or activity of complement in serum or plasma can be divided into three main categories: a) total complement function or activity test; b) individual components activity test; c) complement activation products test, including split products and protein complexes.

a) Total Complement Activity Test

The total complement activity contributes to a comprehensive understanding of the activation status of the complement system to better define disease occurrence, severity, and response to treatment. Therefore, the total complement activity test has very important clinical value in the diagnosis and subsequent treatment of complement-related diseases. The most common methods for testing the functional activity of the complement system include hemolysis assays, liposome lysis, and enzyme-linked immunosorbent assays (ELISAs).

b) Individual Components Activity Test

Regardless of functional activity, individual complement components can be measured by immunodiffusion (RID) or nephelometer techniques, ELISA or Western blot. In routine testing, the most commonly measured complement components are C3, C4, and B factors, followed by C1 inhibitors and other components to verify the diagnosis of complement-associated diseases. In most cases, these immunochemical assays can be used as an alternative to functional tests for individual components. If a defect can be verified by immunochemical methods, further functional tests are not required. If the immunochemical assay does not show any deficiency, a functional test must be performed to further verify the diagnosis. The most common method of detecting the functional activity of individual complement components is to test the sample's capability to reconstitute the hemolytic activity of serum lacking the protein. In order to finally prove that only one component is missing, purified functional active components can be added to the serum to restore the hemolytic activity of the corresponding pathway.

c) Complement Activation Products Test

Generally, total hemolytic activity and individual component measurements can be used as first-level screening techniques, but they are not sufficient to detect pathologically increased complement activation. The complement activation products are only produced when complement is activated, so the complement activation products test can reflect the actual activation state of the complement system under pathological conditions. Over the past two decades, highly specific monoclonal antibodies have been generated that recognize only neoepitopes exposed in the activation product, which enables direct capture of complement activation products by ELISA or high-capacity immunosorbents without the interference of the nonactivated component. A number of complement activation products have been tested by this method, including the classical pathway (C1rs-C1 inhibitors, C4d and C4bc), alternative pathways (Ba, Bb, and C3bBЬP), C3 (C3a, iC3b/C3bc, and C3d) and terminal reactions sequence (C5a and sC5b-9).

Different types of assays are available in Creative Biolabs:

1. Hemolytic Inhibition Assay
2. Complement Inhibitor Validation
3. Receptor Ligand Binding Assay

Creative Biolabs has years of experience in in vitro complement testing with human and animal serum, providing high-quality complement function or activity test services that not only detect complement deficiencies of all three pathways selectively and reliably, but also be used to evaluate complement activation in research applications.

In addition, we also provide our customers with other complement testing services for specific disease’ diagnosis as well as various CRO services. If you want to know more, please feel free to contact us.

Protocols

Hot Complement Assay Reagents

Resources

Complement Activity/Function Assay Products

Complement Testing Services

ComPLET^TM Hemolysis Assay Solutions

• Complement Autoantibody Test
• Complement Genetic Test
• Total Complement Activity Test
• Individual Components Activity Test
• Complement Activation Products Test
• Hemolytic Inhibition Assay
• Complement Inhibitor Validation
• Receptor Ligand Binding Assay