Comparison of various in vitro assays for efficacy screening of immunotoxins

Before using immunotoxins in vivo, their efficacy is evaluated in in vitro assays. In this study we compare six different assays for the evaluation of immunotoxins: protein and DNA synthesis inhibition assay, chromium release assay, cell line colony assay, limiting dilution assay and clonogenic assay. All assays except the chromium release assay show specificity of the immunotoxins in appropriate concentrations. The protein and DNA synthesis inhibition assays are easy to perform and, therefore, suitable for initial screening, while the clonogenic assay seems to be the best one for immunotoxin efficacy determination.