A simple method for determining K(A)s of both low and high affinity IgG antibodies

Thomas O'Hare, Marvin B. Rittenberg

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


A rapid and convenient method for measuring affinity constants (K(A)) of IgG antibody-hapten complexes is described. A key advantage of this method is it suitability for quantification of both low and high affinity interactions. A comparison is made of the K(A)s of the low affinity anti-phosphocholine (PC) antibody T15 (K(A) = 2.9 x 105 M-1) and five heavy chain complementarity determining region 2 (HCDR2) mutant antibodies expressed as IgG2b transfectants. As a demonstration of the general applicability of the technique, colchicine binding to the high affinity monoclonal IgG2a antibody C44 (K(A) = 1.5 x 109 M-1) is measured also; thus the assay is applicable over a four-log range of affinities. The assay, based upon use of fixed Staphylococcus aureus Cowan I strain cells as an adsorbent for antibody- radiolabeled antigen complexes, is conducted over a range of hapten concentrations at constant antibody concentration. The K(A) is obtained by Scatchard analysis.

Original languageEnglish (US)
Pages (from-to)161-167
Number of pages7
JournalJournal of Immunological Methods
Issue number1-2
StatePublished - Sep 1 1998


  • Affinity constant
  • Colchicine
  • Phosphocholine
  • Protein A

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology


Dive into the research topics of 'A simple method for determining K(A)s of both low and high affinity IgG antibodies'. Together they form a unique fingerprint.

Cite this