[en] The apparatus incorporates a steel container for samples of biological biopolymers in conjunction with a co-precipitator, filtration unit and scintillator. An electrical drive is employed for stepwise movements of the system. A control unit is included for regulation of the degree of radio activity. The various reagents are contained in separate vessels. A vacuum pump is employed for the filtration process. The measuring cylinder is a hollow unit made of polyfluoroethylene with end surfaces of film of the same material. Carbon dioxide under presure is used as a control medium. (G.C.)