Radioiodinated lipoproteins: absorption of 125I radioactivity by high density solutions

Concentrations of potassium bromide commonly used for separation of lipoproteins were shown to cause absorption of 125I and thus reduce the counting efficiency of the labeled lipoproteins. Chloroform was shown to cause a 50% reduction in counting efficiency of lipid from 125I-labeled lipoprotein. No reduction of counting efficiency was observed in the presence of high density solutions when 131I was used as label.