摘要:
A method of quantitative analysis of microscopic biological specimens in a fluid medium is disclosed in which the specimens are rendered magnetically responsive by immunospecific binding with ferromagnetic colloid. A known quantity of magnetically-responsive marker particles are added to the fluid medium. The fluid medium is then subjected to a magnetic separation process, to collect the magnetic species from the fluid. The collected species are resuspended in a second fluid medium, and the relative quantities thereof are enumerated to determine the concentration of the desired biological specimen in the first fluid medium. The marker particles may comprise magnetic particles having a relatively large magnetic moment, a magnetic moment approximately equal to the magnetically-labelled biological speciment of interest, or both in order to compensate the determination for variations in immunospecific binding affinity and/or magnetic collection efficiency. The present method is useful for conducting hematological assays, such as red blood cell counts and related determinations. In the case of red blood cells, the specimens may be rendered magnetically responsive by reduction of the iron atoms present in hemoglobin. The enumeration step of the method may be conducted with such equipment as a flow cytometer, or by a novel optical scanning magnetic cell immobilization apparatus.
摘要:
Biological entities such as cells, microbes, or components thereof are labeled with a magnetic colloid containing microscopic magnetic particles. The magnetic particles have a coating capable of biospecific or non-specific binding with the entities. An immobilization apparatus includes a non-magnetic vessel having a ferromagnetic collection structure for attracting the entities toward a collection surface upon which the magnetically labeled entities are immobilized subsequent to placement of the vessel on a support between two magnets. The ferromagnetic collection structure preferably has a sharp edge or high curvature for intensifying the magnetic field and for collecting the entities in a monolayer. The vessel includes an un-obstructed observation path so that immobilized entities may be observed and/or manipulated. The ferromagnetic collection structure may be arranged in various two dimensional patterns to provide a desired collection configuration. The apparatus may further have inlet and outlet ports for allowing a flow of liquid reagent through the vessel for washing or straining the immobilized entities. The support can be translated so that a shoulder on the collection structure concentrates the collected entities by movement of the shoulder in a transverse direction relative to the magnetic field.
摘要:
A method is provided for direct coating of transiently stable, colloidal particulate magnetic substrates with various synthetic or naturally-occurring polymers, particularly biologically-active peptides and proteins. The resulting coated resuspendable, colloidal magnetic particles are particularly adapted for use in bioanalytical procedures involving affinity separation, or the like. There is also provided a method for selectively binding chemically-treated colloidal magnetic particles to polyelectrolytes, e.g., to facilitate extraction of nucleic acids from cell lysates.
摘要:
A method and device for hanging long or short pants or any other similar articles of clothing that contains a waistband are disclosed. The device, an asymmetric hanger, hangs folded pants from the waist and is composed of a finger adapted to insert into the top of a pair of trousers engaging the inside of the waistband along with a clamp that clasps the waistband from the outside near the opposite end of the folded pants and that exerts a force away from the finger. The device can be adapted to hang pants from a simple clothes pole to a variety of novel designs that display pants and facilitate removal or hanging.
摘要:
A magnetic-polymer particle, useful in immunoassay techniques and various other biological/medical applications is produced by coprecipitation of transition metals in the presence of a polymer having available coordination sites. These particles are capable of forming stable aqueous suspensions and may be easily resuspended after agglomeration.
摘要:
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. Diseases such as AIDS, tuberculosis or hepatitis can be monitored. This invention also has utility in the fields of bone marrow transplantation, fetal cell research, in vitro fertilization, and gene therapy.
摘要:
A process and apparatus for removing immuno-specifically recognizable substances in the form of immune complexes from a solution. The solution containing preformed immune complexes or immune complexes already present therein is contacted with an adsorbent consisting of non-immunospecific factor such as Clq, rheumatoid factor, Fc receptor and Fc receptor-bearing cells.
摘要:
A highly sensitive assay is disclosed which combines immunomagnetic enrichment with multiparameter flow cytometric and immunocytochemical analysis to detect, enumerate and characterize carcinoma cells in the blood. The assay can detect one epithelial cell or less in 1 ml of blood and has a greater sensitivity than conventional PCR or immunohistochemistry by 1-2 orders of magnitude. In addition, the assay facilitates the biological characterization and staging of carcinoma cells.
摘要:
Separation apparatus and method for separating magnetic and/or magnetically-labeled particles from a test medium.Test medium within a reaction chamber is caused to flow past a collecting surface, and a high-gradient magnetic field is applied to the surface to capture magnetically responsive particles in the test medium. The particles are deflected toward the collection surface by baffles, a spinner, or a sprayer, or are funneled past the surface by a plunger operable to be displaced into close proximity to the surface to provide a narrow flow path for the particle-laden test medium. The particles normally suspended in the medium are separated out of suspension by adhesion to the collection surface. The particles may be resuspended by removal of the surface from the high-gradient field, or removal of the high-gradient field from the surface. The collection surface is a thin-walled non-magnetic material having a plurality of magnetic pole faces positioned therearound.
摘要:
Compositions and methods are disclosed which enhance the microscopic observation and analysis of biological entities such as cells, bacteria and viruses by eliminating interfering magnetic clusters created by naturally occurring aggregators of colloidal magnetic particles. Additionally means for significantly enhancing the magnetic isolation of low antigen density target cells from biological samples are disclosed.