Abstract: A solid phase-sandwich enzyme-immunoassay method for the rapid determination of carcinoembryonic antigen (CEA). The sample to be investigated is incubated with a first CEA antibody, which is bound to a water-insoluble carrier, and a second CEA antibody, to which peroxidase is bound directly or via a biotin/avidin bridge. The immunological reaction can be carried out in one or two steps. By the presence of 0.4-1.0 mol/l of phosphate ions, 0.3-0.4 mol/l of sulfate ions or 0.2-0.4 mol/l of tartrate ions in the immunological reaction or in the second step thereof (insofar as it is carried out in two steps) the incubation time period is shortened considerably. After the immunological reaction, the phases are separated, whereupon the peroxidase activity is measured either in the solid or in the liquid phase as the amount of CEA present in the sample.

Abstract: A method for the stabilization of peroxidase in a medium containing a serum or serum protein by the addition of 4-amino-antipyrine and stabilized peroxidase compositions are described.

Abstract: An industrial filtering apparatus in which the filter cake can be removed automatically by scraping layers of solid from the cake with paring devices which are associated with screw conveyors for transporting the solid to the center of the housing and depositing it in a removal pipe. The mouth of the removal pipe through which the cake falls is completely unobstructed by structural members. The paring devices can also be used in a different mode to smooth out cracks and compact the cake. There is also an independent revolving device for breaking up the cake which can be used in conjunction with a sprinkler head to ensure particularly intensive and intimate washing and slurrying of the cake. The paring device, its associated screw conveyors and the removal pipe can be raised and lowered, as can the device for breaking up the cake, thus making adjustment to any filter cake thickness possible.