Abstract
Serum of 43 patients under digoxin therapy and 6 ampules of high concentration digoxinspiked serum were analyzed by homogeneous enzyme immunoassay (EMIT) and 125 I-radioimmunoassay (125 1-RIA). The correlation coefficient was 0.923 and the regression line was Y= 1.235 X-0.195 (Y: EMIT, X: 125 1-RIA). Hourly change in the EMIT digoxin assay was determined by 2 specimens of control serum containing 1.0 and 3.0ng/ml of digoxin, and 3 specimens of mixed serum of patients. The coefficient of variation (CV) was less than 5.1%. Daily change in the assay was determined by 5 calibrators for 7 months and a control serum containing 1.0ng/ml of digoxin for 5 weeks. The CV was less than 7.1%. EMIT digoxin assay was thus recognized as a good substitute for RIA method especially it is recommended in hospital laboratories.
