The bovine complement system

Adv Exp Med Biol. 1981:137:413-30.


Methods were developed for titrating bovine C3b-inactivator, C2, C3 and C4 by non-hemolytic means, and for assaying by hemolysis all the components of the bovine classical complement system except C2. All components were detected at serum dilutions above 1:1000, and some at dilutions above 1:100,000. C1, C4, C5, C7 and C9 titers were very high in adult bovine serum, and C2 and C8 were relatively low. C1, C2, and C8 were quite heat-labile at 56 degrees C, and C7 was moderately so, while C3 amd C6 titers increased after heating due to inactivation of a heat-labile inhibitor. Fetal bovine serum contained approximately 1-3% of adult levels of conglutinin, C1 and C6, and 5-50% of adult levels of the remaining components except C3. C3 antigen was found, but C3 functional activity was undetectable in most fetal bovine sera, though present at low levels in a few.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Animals, Newborn / immunology
  • Cattle / immunology*
  • Complement C1 / analysis
  • Complement C1 / immunology
  • Complement C2 / immunology
  • Complement C3b Inactivator Proteins / analysis
  • Complement C3b Inactivator Proteins / immunology
  • Complement C4 / analysis
  • Complement C4 / immunology
  • Complement Fixation Tests
  • Complement Pathway, Classical
  • Complement System Proteins / analysis
  • Complement System Proteins / immunology*
  • Fetus / immunology
  • Guinea Pigs
  • Hot Temperature
  • Methods


  • Complement C1
  • Complement C2
  • Complement C3b Inactivator Proteins
  • Complement C4
  • Complement System Proteins