A test set for a photometric measuring device includes a mixing container which receives a first fluid in its interior and a closing element which is removable from its filling opening, and a dosing container which contains a second fluid in a sealed hollow chamber, with the hollow chamber being sealed on one side by a displaceable sealing plunger and on the opposite side by a movable plug, and with the dosing container being insertable in a sealing manner into the filling opening of the mixing container. For the purpose of simplifying the input of the sample, the dosing container includes an integrated sample-taking device which, after the insertion of the dosing container in the filling opening of the mixing container, is in contact with the first fluid present in the mixing container.