[en] A combined treatment of alginate administered both in intraperitoneal injections and in the diet with a starch containing dough, increases up to 5 times the concentration of ⁸⁵Sr in the blood of mice with a 9-week-old radiostrontium contamination. This combined treatment overcomes the decrease of urinary ⁸⁵Sr excretion, formerly obtained with alginate diets. The availability of the mobilised ⁸⁵Sr for renal excretion, for fecal excretion and for equilibrium between blood and organs is different depending on the mobilizing treatment (injection or diet). The radiostrontium content of liver, kidney and spleen is also increased four to six times by the combined treatment. (author)