UNIT 13.7 Assays for Complement Proteins Encoded in the Class III Region of Human MHC

  1. Lilian Varga,
  2. George Füst

Published Online: 1 JUL 2005

DOI: 10.1002/0471142735.im1307s67

Current Protocols in Immunology

Current Protocols in Immunology

How to Cite

Varga, L. and Füst, G. 2005. Assays for Complement Proteins Encoded in the Class III Region of Human MHC. Current Protocols in Immunology. 67:13.7:13.7.1–13.7.20.

Author Information

  1. Semmelweis Medical University, Budapest, Hungary

Publication History

  1. Published Online: 1 JUL 2005
  2. Published Print: JUN 2005


Investigation of the complement proteins encoded in the class III region of the human MHC isclinically significant. A low level of components that make up the classical pathway is indicative of an underlying in vivo complement activation or primer complement deficiency. Hemolytic tests of C4 and C2 described are the only methods that allow quantitification of the functional complement proteins. The application of these sensitive techniques is unavoidable if inactive complement proteins are present. The complex hemolytic titration process protocol described in detail makes possible the use of this test. Assays to determine complement components belonging to the MHC III region were completed by a basic phenotyping test of the standard factor B alleles. This simple technique is a very useful first-step assay for clinical laboratories engaged in genetic studies.


  • functional C2;
  • functional C4;
  • factor B phenotyping;
  • MHC III;
  • hemolytic assay;