Laboratory problems in digoxin radioimmunoassay

This review discusses the various technical problems likely to be encountered in digoxin assay using 125I methods. Many of these difficulties are not limited to digoxin, but are potential dangers when measuring a wide variety of substances by radio-ligand techniques. Emphasis is placed on ways to avoid or solve these problems. Beside error induced through technical aspects, which include radio-ligand reagents, dispensing equipment, and well counters, other potential sources of interference which are considered are the effects of medications, serum proteins, and previously administered radioactivity.