Abstract: A cartridge includes a male end, a female end and an internal chamber defined by a filter adjacent the male and female ends. The cartridge is specifically designed to be stackable with additional cartridges, as the male end of one cartridge can close the female end of a different cartridge. The cartridges are useful in holding samples for analysis.

Abstract: A novel class of cross-linking agent, which comprises a monomeric organic compound having at least two hydroxyl groups each bonded to a different carbon atom, wherein said hydroxyl groups are activated by reaction with 2-fluoro-1-methylpyridinium toluene-4-sulfonate (FMP). Suitable monomeric organic compounds include diols and polyols. Such cross-linking agents may be conveniently prepared by reaction of the monomeric organic compound with FMP in a suitable solvent, followed by recovery of the resultant reaction products, e.g., via precipitation and filtration. The novel cross-linking agents have a wide variety of uses, including the interconnection of subunits of multimeric enzymes and the covalent immobilization of organic ligands to suitable carriers or supports.

Abstract: A novel class of cross-linking agent, which comprises a monomeric organic compound having at least two hydroxyl groups each bonded to a different carbon atom, wherein said hydroxyl groups are activated by reaction with 2-fluoro-1-methylpyridinium toluene-4-sulfonate (FMP). Suitable monomeric organic compounds include diols and polyols. Such cross-linking agents may be conveniently prepared by reaction of the monomeric organic compound with FMP in a suitable solvent, followed by recovery of the resultant reaction products, e.g., via precipitation and filtration. The novel cross-linking agents have a wide variety of uses, including the interconnection of subunits of multimeric enzymes and the covalent immobilization of organic ligands to suitable carriers or supports.

Abstract: A unique hollow fiber bioreactor system and method for the propagation of cells and the production of various cell propagation products is described. The system and method include the use of a flow block holder which allows a dissolved oxygen probe to be calibrated at the same pressure as the media in the bioreactor system.

Abstract: An anaerobic digester for digesting animal manure and other biologically degradable material contains support media for enhancing the contact between the microbes in the digesting mass and the available nutrients. The digester includes a novel fluid circulation and distribution system. The distribution system prevents build up of heavy material in the bottom of the digester and prevents agglomeration of light material at the top of the digester. The digesting fluid travels over a floating weir into an intake and impeller assembly. The impeller drives the fluid through a conduit located adjacent the floor of the digester. Nozzles in the conduit project the fluid downwardly toward the floor thus causing a sweeping action on the floor. Fluid then flows upwardly past the support media. Risers are provided at the ends of the conduit, which terminate in nozzles at the surface of the digesting liquid.