STUDIES OF MONOCLONAL AND POLYCLONAL ANTI-DIGOXIN ANTIBODIES FOR SERUM DIGOXIN RADIOIMMUNOASSAY

The advantages of monoclonal antibodies (produced by mouse plasma cell-myeloma cell hybrid lines) and those of conventional antibodies were compared in the radioimmunoassay of digoxin. Antibodies produced by some hybrid cell lines (hybridomas) were highly specific for the digoxin structure; this way the cross-reactions to related structures (e.g. spironolactone) could be avoided. When the hybridoma lines were grown in mouse ascites, the resulting fluid could have as high or higher titer than the serum of a hyperimmunized rabbit. The high titer, the specificity and the permanent growth of the hybridoma lines make them an optimal source of the specific antibody in clinical radioimmunoassays for the measurement of drug or hormone levels.