Abstract: A macroglobulin is used to improve the signal-to-background ratio in an affinity binding assay employing a proteinase (or precursor) as a label. The macroglobulin entraps unbound labeled reagent, thereby reducing its signal generating activity, relative to that of the affinity complex.

Abstract: There is disclosed a method of culturing cells which produce products and identifying the thereby produced products, characterized in that the cells are cultured on the surface of a quantity of growth medium, which surface has been divided into a plurality of growth areas thereby limiting the amount of growth-medium which is available to the cells so that these reach metabolic stage in which said products are produced, and identifying the thereby produced products by an in situ screening procedure.

Abstract: Disclosed are immunofluorescence staining methods which increase the likelihood that antibodies expressed by a single B cell selected and sorted by fluorescence activated cell sorting are specific for the antigen of interest, and which also allow selection of B cells expressing antibodies of high affinity for the antigen of interest. The antigen-specific single B cells are to be used in a procedure which amplifies and selects their V.sub.H and V.sub.L sequences. The selection for B cells expressing antibodies to specific antigens is increased by labeling B cells with at least two antigen probes, where each antigen probe includes the antigen of interest and the difference between the two probes is that each is labeled with a different fluorochrome. The positive selection achieved using antigen probes with two different colors is preferably combined with a negative selection step, in which autofluorescent cells and sticky cells exhibiting fluorescence for the third irrelevant surface marker are excluded out.

Abstract: A liposome reagent encapsulating a molecule to be targeted to a body site or used as an assay reporter has a ligand and a sulfonate-containing group on the liposome surface. Preferred ligands are antibodies or antibody fragments and preferred encapsulants are enzymes or dyes. In the most preferred reagents, the antibody and sulfonate-containing group are covalently bonded to the liposome surface through a connecting group which includes a succinimidyl group resulting from addition of the ligand or sulfonate-containing group to a maleimidyl group. The invention includes a kit of materials for performing an assay using the reagent of the invention as the tracer.

Abstract: A method for classifying and monitoring leukemias is disclosed. The method comprises mixing cells from a patient with a plurality of fluorescently labelled monoclonal antibodies, examining the cells by means of flow cytometry, scoring the percent of positive cells in each quadrant in a two-dimensional plot of log fluorescence and comparing the scores with a standard. Monitoring of the disease also may be achieved by comparing the scores before, during and after treatment.

Abstract: Disclosed is a method for the screening of pathological condition in the intestinal tract of an animal or a human being, e.g., intestinal ischemia, necrotizing enterocolitis, inflammatory bowel disease and bowel graft rejection. The method assays elevated levels of lipid binding protein, more particularly intestinal fatty acid binding protein, in a biological sample obtained from the animal or human being. Serum or urine are preferred biological samples. Preferred methods employ an immunological assay such as a radioimmunoassay or an enzyme-linked immunosorbent assay for the detection of intestinal fatty acid binding proteins in the sample.

Abstract: Disclosed are immunofluorescence staining methods which increase the likelihood that antibodies expressed by a single B cell selected and sorted by fluorescence activated cell sorting are specific for the antigen of interest, and which also allow selection of B cells expressing antibodies of high affinity for the antigen of interest. The selection for B cells expressing antibodies to specific antigens is increased by labeling B cells with at least two antigen probes, where each antigen probe includes the antigen of interest and the difference between the two probes is that each is labeled with a different fluorochrome. The specificity of sorting of the desired B cells can be further enhanced by staining those antigen-specific B cells which produce the immunoglobulin isotype (typically IgG), with targeting molecules reactive with B cell markers, such as .gamma. chain and CD19, that are conjugated with different fluorochromes.

Abstract: The present invention provides a process for the detection of analytes in body fluids containing free biotin by immunoassay with the use of biotin conjugates for the labelling, immobilization or complexing of immunological reagents, wherein the biotin present in free form is removed from the immunological reaction by incubating the sample solution with polymer particles consisting of a core and a covering which, as core, contain a polymer which has a plurality of binding sites for biotin and, as covering, at least one layer of protein, peptide, carbohydrate or co-polymer of carbohydrate and amino acids, the layer thickness of the covering being so adjusted that the coating is permeable for the free biotin but not for the biotin conjugate.