Abstract: A blood-culture flask with an integrated subculture. It comprises a flask proper that can be filled with a liquid nutrient solution and has a neck with an outside thread, a support that can be coated with a solid culture medium, a resilient stopper with an edge that projects at one end, and a screw cap. The screw cap consists of a bottom that is open above and below and has an inside thread and of a top that is open below. The inside thread is dimensioned so that it can be screwed down over the outside thread on the neck of the flask so that the upper edge of the thread is below the upper edge of the neck when screwed on. The resilient stopper is positioned inside the bottom of the screw cap so that the bottom surface of its resilient projecting edge comes to rest against the offset above the thread when not screwed on and its lower section is dimensioned so that it can be introduced tight into the neck of the flask.

Abstract: In a device for testing air for microorganism content with a rapidly rotating impeller inside a cylinder that has a backing sheet coated with culture medium against its inside surface, microorganisms that vary more extensively in size can be detected with almost equal effectiveness, the throughput of air can easily be determined, and the precipitation effect can be precisely tested because the backing sheet rotates along with the impeller, the blades of the propeller are at a low angle to the plane it rotates in, the air enters at a location that is separate from the location at which it leaves, through inlets from above and down and out through outlets, and the inner surface of the rotor below the impeller chamber is in the form of a channeling cylinder.