Abstract: A method and apparatus for automatically and rapidly, retrieving, counting and/or analyzing at least one selected white blood cell population and/or subset thereof of an aged whole blood sample or portion thereof. A volume of a biological sample containing the white blood cells is prepared and at least one reactant specific or preferential at least to some selected biological cells is introduced thereto and rapidly mixed for a short period of time. The total white blood cell populations and lymphocyte population are first electronically counted and then the neutrophil population including the aged neutrophil population is removed from the same or a second sample portion. The opacity and/or volume parameter of the cells then can be modified and the mixture then again is counted and analyzed in one or more steps to obtain the desired white blood cell population analysis.

Abstract: A method and apparatus for automatically and rapidly, retrieving counting and/or analyzing at least one selected population of cells or formed bodies, such as a white blood cell population and at least one subset thereof of a whole blood sample or portion thereof. A volume of a biological medium containing the white blood cells is prepared and at least one reactant specific or preferential at least to some selected biological cells is introduced thereto and rapidly mixed for a short period of time. A multipart blood cell analysis is obtained with a single sensing parameter by depleting at least one WBC subset population. The percentage of a desired WBC population subset or the overlapping of WBC subset populations also can be obtained by subtracting one or more obscuring WBC subset populations.

Abstract: A method for sampling, metering and delivering precise microliter volume aliquots of a liquid blood sample to mixing and testing means of an electronic blood analysis system for analysis using a sampling and metering valve assembly in which is defined plural through fluid flow paths, one of the flow paths including a loop for metering and isolating a sample aliquot therein, the method comprising the steps of defining first and second dedicated passages within the valve assembly displaced one from the other and from the loop containing the isolated aliquot, introducing an inert gas to the loop to force the aliquot therein to said first dedicated passage at the displaced location thereof, placing the first and second dedicated passages in communicating relationship and introducing lyse reagent to the second dedicated passage to force the isolated aliquot from the first dedicated passage with the lyse reagent to a location exterior of the valve assembly without contaminating any flow paths which has been travers

Abstract: The invention related generally to the preparation of colloidal metal(O) particles having a crosslinked aminodextran coating with pendent amine groups attached thereto. The aminodextran acts as both a reductant for reducing metal ions to metal(O) particles and as the protective agent which coats the metal(O) particles thus formed. After stabilizing the aminodextran coating by use of a crosslinking agent, the coated particles can be used to covalently bind proteins. The resulting protein containing colloidal particles can be used as markers in optical and electron microscopy, in immunological and biological assays, and possibly as therapeutic agents.

Abstract: A method is described for the preparation of uniform colloidal particles of ferrites, containing manganese(II), at a relatively low temperature in the presence of an aminodextran solution which acts as a support vehicle for the nucleation and growth of colloidal particles of metal oxide and for dispersion as separate single particles.

Abstract: A microfilm camera/processor including an electrophotographic medium mounted for successive translation step by step over plural functional stations for performing functional operations successively on portions thereof, the stations being an electrostatic spin charging station, an exposure station including a shutter mechanism forming an latent charge image, a toning station including a planar development electrode, a liquid toner depositing feed and a mechanism for bringing the electrode surface into and out from close proximity to the latent charge image, a cleaning and drying station forming a dried toner image and a dry transfer station to force the dry toner image below the surface of a softened coating carried by a strip film receptor and a preprogrammed control .

Abstract: A method and apparatus for accelerating at least one definitive biological reaction including increasing the accuracy of determinations made therefrom. The reaction involves selected viable biological cells which are prepared in a small sample volume and rapidly mixed with microspheres having antibody specific at least to specific ones of the cells bound thereto. The microspheres can be magnetic and the bound cells can be magnetically removed to analyze the remaining blood cell populations. The microspheres can be introduced sequentially or simultaneously.

Abstract: A method and apparatus for automatically and rapidly, retrieving, counting and/or analyzing at least one selected population of cells or formed bodies, such as a white blood cell population and at least one subset thereof of a whole blood sample or portion thereof. A volume of a biological medium containing the white blood cells is prepared and at least one reactant specific or preferential at least to some selected biological cells is introduced thereto and rapidly mixed for a short period of time. The opacity and/or volume parameter of the cells can be modified and the mixture is then counted and analyzed in one or more steps to obtain the desired white blood cell population and subset analysis. The biological sample can be a whole blood sample and the reactant can include or be a lyse or a monoclonal antibody bound to microspheres, which will bind to specific ones of the cells or a combination of lyse and microspheres with antibody bound thereto.

Abstract: A method and apparatus for automatically and rapidly, retrieving, counting and/or analyzing at least one selected white blood cell population and/or subset thereof of a whole blood sample or portion thereof. A volume of a biological sample containing the white blood cells is prepared and at least one reactant specific or preferential at least to some selected biological cells is introduced thereto and rapidly mixed for a short period of time. The opacity and/or volume parameter of the cells can be modified and the mixture is then counted and analyzed in one or more steps to obtain the desired white blood cell population analysis.The biological sample can be a whole blood sample and the reactant can include or be a lyse or a monoclonal antibody bound to microspheres, which will bind to specific ones of the cells or a combination of lyse and microspheres with antibody bound thereto.

Abstract: A single filtration device containing coated filter membranes and absolute pore filters is provided in which the membranes and absolute pore filters are present in two sections of the filter device. The filter device will remove up to about 98% of the endotoxins in addition to removing viruses with an efficiency of at least 4.6.times.10.sup.5 and DNA to less than 10 picograms per 500 mg sample.

Abstract: A control slide for use in an immunoassay having a section of a cell pellet retained on the slide in a stable and substantially permanent formation which can be stored at room temperature. Further, the invention includes the method of making the control slide.

Abstract: A method for preparing a phycobiliprotein-Texas Red conjugate which overcomes the energy transfer/fluorescent quenching dilemma is disclosed. A phycobiliprotein, such as phycoerythrin, is conjugated with dye, such as Texas Red, in the presence of a selective salt which causes a hydrophobic intramolecular rearrangement of the phycobiliprotein thereby exposing more hydrophobic sites for binding to Texas Red. The conjugate is useful in multiple color fluorescence assays without requiring the use of multiple exciting sources.

Abstract: The invention relates generally to colloidal particles having a crosslinked coating with pendent functional groups attached thereto. Magnetic and non-magnetic particles have a biodegradable, crosslinked gelatin coating to which is covalently attached pendent biological substances or molecules, especially monoclonal antibodies. The monoclonal antibodies so attached are useful in a variety of positive and negative biological assays.

Abstract: An antibody-enzyme conjugate is prepared having an enzyme to antibody ratio of approximately 3. The conjugate is produced by adding sulfhydryl groups to an antibody and maleimidyl groups to an enzyme to produce a modified antibody and enzyme, and reacting the modified antibody and enzyme to produce the conjugate. In producing the modified antibody and enzyme, about a 15 molar excess of reagents for introducing sulfhydryl and maleimidyl groups is used. When reacting the modified antibody and enzyme, a four molar excess of the modified enzyme is used, and reacting is stopped after a specified period of time by addition of selective reagents. The selective reagents may be cysteine and iodoacetamide.

Abstract: A hybrid cell line is provided which is capable of producing monoclonal antibodies which binds to HTLV-I and HTLV-II core antigens p24 and p53; but does not bind the p19 core antigen. The antibody also binds to core antigens of simian T-cell leukemia virus Type I (STLV-I). The monoclonal antibody is identified as the KC-88 monoclonal antibody. The cell line which produces the KC-88 monoclonal antibody has been deposited in the American Type Culture Collection, Rockville, Md. and assigned A.T.C.C. Deposit No. HB 10562.

Abstract: A liquid metering and transfer valve assembly having the capability of metering, isolating, transfering and delivering precise microliter volume aliquots of a blood sample, from a source thereof, to mixing and testing chambers of an electronic blood analysis system for analysis, and further, carrying a loop for metering and isolating an additional sample aliquot within the valve assembly in the loop, a first dedicated passageway for introducing a first fluid to the loop to force the additional aliquot from its isolated location to a first dedicated portion of the valve assembly displaced from the loop and a second dedicated portion of the valve assembly to establish a flow path for introducing a lysing reagent to the first dedicated portion to force the additional aliquot from its displaced disposition, as a lyse reagent/aliquot mixture, to a selected additional mixing and testing chamber exterior of the valve assembly without contaminating any interior flow path traversed by a blood sample and associated dil

Abstract: A monoclonal antibody which binds preferentially to a subset of the human CD4+ lymphocyte population whereby to positively and precisely distinguish between helper-inducer and suppressor-inducer cells in the CD4+ cell population. The monoclonal antibody recognizes a novel antigen on the CD4+ lymphocytes by means of which it can bind CD4+ cells which express the antigen on the surface of CD4+ cells. The CD4+ subset cell population to which this antibody preferentially binds is the CD4+ helper-inducer population. This selectivity of the monoclonal antibody enables cell sorting, diagnostic and possible therapeutic applications thereof to be realized. The monoclonal antibody also reacts with CD8 cells, B cells and macrophages.

Abstract: For use in automated or semi-automated hematology analysis apparatus, a method of introducing a volume of blood from a source thereof along a conduit leading to a sampling, metering and transfer valve assembly of the apparatus comprising the steps of drawing a predetermined volume of blood sample from the source, causing the drawn blood sample to travel along the conduit toward the valve assembly, providing detectors adjacent the inlet and outlet of the valve assembly and using vacuum to position the drawn blood sample so that it passes through the valve assembly and is disposed in metering condition within the valve assembly, the positioning being responsive to signals provided by the detectors.

Abstract: A single filtration device containing coated filter membranes and absolute pore filters is provided in which the membranes and absolute pore filters are present in two sections of the filter device. The filter device will remove viruses, as modeled by type-C Xenotropic retrovirus, with an efficiency of at least 4.6.times.10.sup.5 ; remove DNA from levels of 10 .mu.g/sample to levels below 10 picograms per 500 mg sample of monoclonal antibody; and will remove at least 97% of some bacterial endotoxins.

Abstract: A method is described for the preparation of uniform colloidal particles of ferrites, containing manganese (II), zinc(II), barium(II), iron(II), cobalt(II), or nickel(II), or a mixture of manganese(II) and zinc(II), at a relatively low temperature in the presence of a gelatin solution which acts as a support vehicle for the nucleation and growth of colloidal particles of metal oxide and for dispersion as separate single particles.