An assay that predicts the ability of monoconal antibodies to form potent ricin A chain-containing immunotoxins

M. Till, R. D. May, J. W. Uhr, P. E. Thorpe, E. S. Vitetta

Research output: Contribution to journalArticle

31 Scopus citations


In this report, we describe an assay for screening monoclonal antibodies for their cytotoxic potential as ricin A chain-containing immunotoxins. The assay involves treating cells with dilutions of the test antibody followed by a Fab fragment of a secondary antibody coupled to ricin A chain ('indirect assay'). The cytotoxicity of the indirect assay is compared to that of the direct assay where the monoclonal antibody is coupled to ricin A chain. Indirect and direct assays were carried out using 14 antibodies and a panel of 8 human and mouse cell types. The two assays showed virtually 100% correlation. The indirect assay, therefore, predicts the potency of a given monoclonal antibody to make an effective immunotoxin and should be useful in screening monoclonal antibodies for use as immunotoxins.

Original languageEnglish (US)
Pages (from-to)1119-1123
Number of pages5
JournalCancer Research
Issue number5
Publication statusPublished - 1988


ASJC Scopus subject areas

  • Cancer Research
  • Oncology

Cite this