Abstract: Magnetic particles with an outer glass surface being essentially poreless or having pores of a diameter of less then 10 nm as well as ferromagnetic particles with a glass surface are preferentially useful for the isolation of biological material from samples. They provide a quick and reliable purification.

Abstract: Preparations of particles having a glass surface, wherein more than 75% by weight of these particles have a particle size between 0.5 &mgr;m and 15 &mgr;m and a glass surface which contains between 2 and 6 mole % zinc oxide, have proven to be particularly advantageous in processes for the purification of nucleic acids. This in particular results in an increased nucleic acid yield.

Abstract: Preparations of particles having a glass surface, wherein more than 75% by weight of these particles have a particle size between 0.5 &mgr;m and 15 &mgr;m and a glass surface which contains between 2 and 6 mole % zinc oxide, have proven to be particularly advantageous in processes for the purification of nucleic acids. This in particular results in an increased nucleic acid yield.

Abstract: Magnetic particles with an outer glass surface being essentially poreless or having pores of a diameter of less then 10 nm as well as ferromagnetic particles with a glass surface are preferentially useful for the isolation of biological material from samples. They provide a quick and reliable purification.

Abstract: Magnetic glass particles are prepared containing a magnetic core coated with a glass layer having a substantially pore-free glass surface. The particles are used for separating biological material such as nucleic acids. A preferred process of preparing the particles is by forming a mixture of magnetic cores with a sol formed from an alcohol and a metal alkoxide, spray-drying the mixture to coat the cores with a layer of gelled sol, and heating the coated cores to obtain the magnetic glass particles. Preferably, the particles have an average particle size of less than 100 &mgr;m and any pores of the glass surface have a diameter of less than 10 nm. The magnetic core may be a composite material containing a mica core and magnetite particles immobilized on the mica core, and the glass layer may contain boron oxide. Magnetic core materials include magnetite (Fe3O4) and Fe2O3.

Abstract: A seal arrangement for sealing a shaft with respect to a housing containing a fluid comprises a face seal exposed to a buffer gas on a portion thereof facing away from the fluid. Disposed upstream of the face seal at the fluid said portion thereof is a collecting chamber for receiving a leakage of the buffer gas having gained access to the fluid-side portion of the face seal. The collecting chamber is in communication with an external separating means for separating the gas phase from the fluid phase of a gas/fluid mixture having collected in the collecting chamber. The fluid phase can be returned into the interior of the housing.