Abstract: A material and method are described to reduce the non-specific binding of a labelled material, wherein the labelled material comprises a fluorochrome and a specific binding pair member. The invention is particularlly suited to the lysis of peripheral blood wherein a labelled material is used to identify and detect cell populations within a sample of blood.

Abstract: Reagents and methods for intracellular staining of anionic materials as provided. The inherent staining characteristics of a fluorescent molecule may be suitably altered by covalently linking a plurality of said molecules to a nonimmunoglobulin derived cationic polymer having the desired staining specificity. By careful selection of the net charge and size of the dye polymer complex, diffusion through the cellular membrane can be enhanced and an enhanced fluorescent signal obtained by localization of a plurality of fluorescent molecules at the site of interest.

Abstract: A method is provided for discriminating white blood cells from red blood cells and platelets in an unlysed, whole blood sample. The white blood cells may be discriminated into five subpopulations: lymphocytes, monocytes, neutrophils, eosinophils and basophils. A red light absorbing fluorescent dye is utilized along with a measurement system comprised of a red light source and suitable detectors for red fluorescence, forward light scatter and right angle scatter.

Abstract: Lysing reagents for use in flow cytometry instruments. Lysing reagents suitable for lysing red blood cells are provided thereby permitting 3-part differential counting of white blood cells. The reagents comprise a leukoprotective agent for preserving the lymphocyte cellular integrity during analysis, and buffers adjusted to provide the correct pH environment for optimal lysis and activity. Preferred embodiments will additionally incorporate non-ionic preservatives in very low concentrations.

Abstract: Methods for the determination of phagocytic and killing ability of selected leukocyte subclasses based upon the use of three part differentials obtained by light scatter characteristics and gated fluorescence. Particles having multiple fluorescent labels associated therewith, one of which is sensitive to reactive oxygen, incubated with the leukocytes. Detection of the fluorescent labels permits identification of cells having phagocytic ability, as determined by presence of the non-sensitive label, and also the identification of those with killing ability as determined by the decrease in fluorescence from the sensitive label.

Abstract: An immunological substance detecting reagent is provided which, in the preferred embodiment, employs an immunological homolog specific for the immunological substance to be detected coupled to a water-soluble polymer having a net charge not greater than zero. The water-soluble polymer further has associated a plurality of marker substances such as fluorophore molecules thereby providing a reagent of increased sensitivity for the detection of an antigen-antibody immunological reaction.