Abstract: The present invention relates to an agent for intravascular administration for diagnostic and/or physiologic investigations, which agent consists of or contains a suspension of minute radioactive particles in a physiologically acceptable liquid.Radioactively labelled microspheres, in suspension in a physiologically acceptable liquid, have lately been increasingly used in circulation studies, studies of the shunting phenomena, microcirculation studies, nutrition studies and as a means for carrying out scintography on man and animals.

Abstract: A dextran derivative gel in particle form for use in the separation of substances according to their molecular size and/or electrical charge by means of gel-chromatographic and/or ion exchange techniques is disclosed which gel comprises a copolymerizate obtained by the free-radical copolymerization of a dextran derivative containing vinyl and/or substituted vinyl groups with (a) a divinyl compound of the formula ##STR1## wherein R' and R" are equal or different and each represent hydrogen or methyl and X is ##STR2## --SO.sub.2 -- or the group ##STR3## wherein n is an integer from 1 to 6, inclusive, and optionally (b) a low-molecular weight monovinyl compound.

Abstract: A dextran derivative gel for use in electrophoretic separation processes is disclosed, which gel comprises a polymerizate obtained by the free-radical homopolymerization of a dextran derivative containing vinylic groups of the formula ##STR1## wherein A is --CH.sub.2 -- or --O-- and R is a hydrogen atom, a methyl group, a trifluoromethyl group, a fluorine, chlorine or bromine atom or a cyano group, or free-radical copolymerization of such a vinylic derivative of dextran with a low-molecular weight monovinyl compound.