Abstract: Apparatus and methods are disclosed which facilitate immobilization of magnetically labelled particulate entities, e.g., cells, preferably in a defined pattern, on a collection surface via binding between specific binding pair members, as an aid to particle analysis.

Abstract: The invention relates to an improved method for the manufacture of magnetically responsive particles, also called ferrofluids. The improved method involves a heat treatment step, which may occur at various times during the preparation of the materials, including during subdivision of the magnetic starting material, during the addion of a coating material, after formation of a magnetically responsive particle, or some combination thereof. The materials formed by such a process have numerous advantages over materials formed by other processes, including enhanced salt stability, increased coating uptake, and increased binding capacity. These ferrofluids have applications in a variety of preparative and diagnostic techniques, including immunoassay, cell separations, toxicity testing, food testing, environmental analysis, and MRI.

Abstract: The invention relates to an improved method for the manufacture of magnetically responsive particles, also called ferrofluids. The improved method involves a heat treatment step, which may occur at various times during the preparation of the materials, including during subdivision of the magnetic starting material, during the addion of a coating material, after formation of a magnetically responsive particle, or some combination thereof. The materials formed by such a process have numerous advantages over materials formed by other processes, including enhanced salt stability, increased coating uptake, and increased binding capacity. These ferrofluids have applications in a variety of preparative and diagnostic techniques, including immunoassay, cell separations, toxicity testing, food testing, environmental analysis, and MRI.

Abstract: A method for separation of a mixture of biological entities into at least three distinct, subpopulations. Different antibodies are provided, with each antibody bound to a solid support in a unique manner such that by a manipulation of the physical or chemical environment, the bonds between the antibodies and the solid supports can be selectively broken. The mixed population of cells is incubated with the antibodies. The cells are magnetically separated from a test medium and collected in a monolayer upon a collection surface. Then by manipulation of the physicochemical environment, specific linkages can be broken and desired cell subpopulations released from the collection surface. This method has medically significant diagnostic and therapeutic applications, as entire cell types can be separated from non-malignant medically vital cell types. Cancer can be diagnosed, staged, and monitored. Genetic analysis from maternal blood, CVS, or amniocentesis samples is possible.