Abstract: A population of T lymphocyte precursor cells is disclosed. In bone marrow, the earliest identifiable T lymphocyte precursor is CD34.sup.+, CD7.sup.+ and Leu 8.sup.+++. Methods of isolation and methods of therapeutic use of such cells also are disclosed.

Abstract: A patient's health is diagnosed by centrifuging blood samples in a transparent tube, which tube contains one or more groups of particles such as lyposomes or plastic beads of different densities for each group. Each group of density-defined particles carries antigens or antibodies which are specific to a complement antigen or antibody which may be in the blood sample being tested, and which are indicative of the patient's health. A label-tagged antibody which is specific to all bound antibody/antigen couples is added to the blood sample so as to form labelled antibody+antigen-antibody complexes (AAAC) in the blood sample. Upon centrifugation, the complexed particles will settle out in different areas in the tube according to the respective density of the particles, and the degree of label emission of the particle layers can enable qualitative or quantitative analyses of the blood sample to be made.

Abstract: A patient's health is diagnosed by centrifuging blood samples in a transparent tube, which tube contains one or more groups of particles such as lyposomes or plastic beads of different densities for each group. Each group of density-defined particles carries antigens or antibodies which are specific to a complement antigen or antibody which may be in the blood sample being tested, and which are indicative of the patient's health. A label-tagged antibody which is specific to all bound antibody/antigen couples is added to the blood sample so as to form labeled antibody+antigen-antibody complexes (AAAC) in the blood sample. Upon centrifugation, the complexed particles will settle out in different areas in the tube according to the respective density of the particles, and the degree of label emission of the particle layers can enable qualitative or quantitative analyses of the blood sample to be made.

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: A method for the non-linear, non-logrithmic transformation of one or more parameters of data gathered by means of flow cytometry is disclosed wherein the method seeks to maximize the resolution between populations of interest for each parameter while maintaining the dynamic range of the data recorded.

Abstract: A method is disclosed for the discrimination between intact and damaged cells in a sample, and more particularly, the method uses a vital nucleic acid dye to selectively stain intact versus damaged cells which then may be counted and sorted by flow cytometry means. The method also may be used in conjunction with fluorescently labelled monoclonal antibodies to simultaneously identify cellular antigens.

Abstract: A method for multi-parameter analysis of cells in a body fluid sample is described which makes use of a plurality of fluorescence measurements, comprising at least two nucleic acid dyes and at least one fluorescently labelled cell surface marker, and a plurality of light scattering measurements. A kit containing the nucleic acid dyes and cell surface marker also is described.