Abstract: Culture vessels for cell cultures having at least one cell culture chamber containing a cell culture mixture that is separated by a dialysis membrane from a nutrient medium in a nutrient supply chamber. Nutrients are transported through the dialysis membrane into the cell culture chamber and metabolic products are transported out of the cell culture chamber into the nutrient supply chamber. To provide a culture vessel for generating cell cultures with a high cell density that is economical to manufacture and easy to handle and to reduce the danger of infections, a gas exchange membrane, that at least partly delimits the cell culture chamber and that is impermeable to liquids and to microorganisms that could contaminate the cell cultures is provided for feeding the gases required for cell culturing to the culture chamber and for discharging the gases generated during cell culturing.

Abstract: To eliminate welds when forming connections from coupling joints of membrane filter structures having two external housing plates between which a membrane filter assembly (3, 4) is positioned, one (2) of the housing plates (1, 2) is formed with a bored or milled, essentially circular recess at each one of the locations where fluid connection couplings (6-9) are to be placed, the fluid connection couplings being formed by a plug element which is clamped in sealing engagement against a sealing bottom wall surface (13) of the respective recess. To provide absolute tightness, even of molecular substances such as bacteria, tissue elements, yeasts and the like, a sealing ring, preferably an O ring (15) is placed in a groove (14) formed in the sealing wall surface (13).

Abstract: To control the speed of an alternating-current drive capacitor motor of a centrifuge, the motor is connected to the bridge arm of a single-phase inverter. The bridge arm is connected at each of its ends to the midpoints of a series circuit of two capacitors and two field-effect transistors, these series circuits being connected in parallel with one another and connected to the output of a rectifier operated by the a.c. voltage supply. During operation, the capacitors are discharged by means of triggering the field-effect transistors alternately via the capacitor motor, the triggering being performed via a microprocessor serving as a pulse generator.

Abstract: A latch is known for a laboratory apparatus, for locking a cover or door on its housing, having a hook 12 in one of the parts to be locked and a lock 1 in the other. The lock has a pivotable locking element 3 with a claw-shaped opening 9 which engages the hook 12 against the pressure of a spring and is releasable from engagement with the hook by an actuating element 7. In order to provide a latch of this kind with means to meet strict safety requirements and ensure secure locking during operation of the apparatus, an additional closing element 4, opening element 5, and securing element 6, which engage one another, are disposed between the locking element 3 and the actuating element 7.

Abstract: An improved method and apparatus for separating high-molecular-weight substances from cells suspended in liquid nutrient media, features continuous central monitoring and control of the process by a computer (22), and a way to combine the heretofore separate processes of first, separating media into solid and liquid components, and second, concentrating the proportion of high-molecular-weight components in the separated liquid. The media are conveyed by a first pump (3) to a centrifuge continuous flow rotor (2), which separates the solids from the liquid components and directs the latter to an intermediate reservoir (5), which sits on an electric scale (7) which is continuously monitored. From here they are fed to a filtration unit (9) in which the high-molecular-weight substances are separated and recycled through a feedback line (11), with the aid of a second pump (10), into the intermediate reservoir (5).

Abstract: A centrifuge is known which has a rotor bearing a plurality of swinging buckets mounted each on two pivots and sector-shaped inserts secured in place on the axis of the rotor shaft. The inserts have substantially vertical, radially disposed supporting walls which receive the thrust of the pivots and their outer part serves as a centrifugal force-supporting surface in the operating state. Two pivots are associated with each sector-shaped insert. In order to construct a centrifuge with swinging buckets such that it will be distinguished by its simple construction and will not require adjustment of the individual components with respect to one another, a pivot is disposed on each of the two supporting walls of the insert with their free ends confronting one another.

Abstract: Centrifuges are known which have a working head placed on a shaft driven by a motor, and in which a longitudinally slotted sleeve is disposed between the shaft and a central bore in the working head. This sleeve is expanded against the bore by a conical spreader driven by a threaded element screwed onto the end of the drive shaft. To create a tight and wobble-free coupling between the working head and the drive shaft of the centrifuge which will be secure even after long use and frequently changing torque, but which will assure easy release, the shaft has a tapered end and on this end, which reaches into the central bore of the working head, is seated the spreader, which is in the form of a bushing with a tapering bore, and the threaded element has on its outer circumference projections which engage indentations in the spreader.