Abstract: 1.alpha.,25-Dihydroxycholecalciferol, also known as 1.alpha.,25-dihydroxyvitamin D.sub.3, calcitriol or 1.alpha.,25(OH).sub.2 D.sub.3, occurs naturally in man as the active form of cholecalciferol or vitamin D.sub.3. The natural supply of vitamin D.sub.3 depends on the conversion of 7-dehydrocholesterol to vitamin D.sub.3 in the skin by ultraviolet light. Vitamin D.sub.3 is then converted to calcitriol in a two-step process in the liver and kidney before its acts on its target tissue.

Abstract: This invention involves an improvement in a method for immunochemically assaying a member of an antigen-antibody binding pair in serum or plasma which utilizes labeled antigen having a plurality of antigenic binding sites as the indicating reagent, the improvement comprising employing the antigen immunochemically bound to labeled Fab as the indicating reagent. This invention also encompasses reagents useful in practicing the above method. These methods and reagents are particularly useful in hepatitis detection.

Abstract: An apparatus useful in expediting the performance of immunochemical determinations which require the complete separation of a solid phase or precipitate from a liquid phase is disclosed. In particular, this apparatus features a test tube rack and cooperating retaining means for spanning said rack and tubes whereby inversion results in a rapid and uniform removal of the liquid contents of each tube while retaining the precipitate or solid phase.

Abstract: A method for detecting endotoxins in body fluids comprising: unmasking endotoxins in the body fluids; separating the unmasked endotoxins from the body fluids by affinity chromatography; and detecting the endotoxins. This method is particularly useful for early detection of life threatening systemic Gram-negative infections.

Abstract: This invention encompasses a standard for determining glycosylated hemoglobin comprising a mixture of hemoglobin or methemoglobin and about 1% to 25% of the 2,4-dinitrophenyl derivative of hemoglobin or methemoglobin wherein a 2,4-dinitrophenyl group blocks the allosteric binding site of hemoglobin or methemoglobin.

Abstract: The present invention encompasses a method for determining ligands in test samples comprising intermixing with the test sample a ligand analog-irreversible enzyme inhibitor conjugate and a binding protein bindable to the ligand and the ligand analog-irreversible enzyme inhibitor conjugate and wherein the amount of ligand analog-irreversible enzyme inhibitor conjugate bound by the binding protein is related to the amount of ligand in the test sample, said binding protein inactivating the irreversible enzyme inhibitor when bound to the ligand analog portion of the conjugate; intermixing an enzyme which is irreversibly inhibited by the ligand analog-irreversible enzyme inhibitor conjugate unbound by the binding protein; and intermixing substrate to the enzyme and monitoring the enzyme substrate reaction.The invention also includes ligand analog-irreversible enzyme inhibitor conjugates useful as reagents in practicing the method.

Abstract: The present invention encompasses a method for determining a class specific antibody to an antigen comprising:(a) binding an antibody for a specific immunoglobulin class to a solid support to form a class specific antibody reagent;(b) reacting the class specific antibody reagent with test sample;(c) removing unbound test sample to provide an antigen reagent, and(d) reacting the antigen reagent with a known antigen and measuring the amount of bound antigen thereby determining the amount of class specific antibody to that antigen.The present invention is useful for differential diagnosis, since the relative amount of class specific antibodies varies with the progress of infection.

Abstract: This invention relates to an immunoassay for carcinoembryonic antigen in plasma or sera. Heat-treating the plasma or serum provides a supernatant which is incubated with a solid support having carcinoembryonic antigen antibody adsorbed thereto. Subsequently, the solid support is incubated with a labeled carcinoembryonic antigen antibody. The labeled antibody on the solid support is measured and compared to standards.

Abstract: This invention encompasses a standard for determining glycosylated hemoglobin comprising a mixture of hemoglobin or methemoglobin and about 1% to 25% of the N-[5-nitrotropon-2-yl] hemoglobin or methemoglobin derivative wherein the allosteric binding site is blocked.

Abstract: A method, reagent and test kit for determining glycosylated hemoglobin in blood samples which involves liberating hemoglobins from red blood cells by chemical or physical means and reacting non-glycosylated hemoglobin with an allosteric site binding substance which reacts with the allosteric binding site of non-glycosylated hemoglobin and thereby alters the distribution between allosteric forms of the hemoglobins and measuring the change. This method is useful in monitoring glucose metabolism for detecting and controlling diabetes.

Abstract: Rectilinear drive apparatus for rapidly and accurately moving a driven component to a desired location with settling of vibration to be achieved immediately after reaching said location; including a frame, a stepping motor drive coupled to the driven component and bearing members slidably mounting the component to the frame. One of the bearing members includes a pair of rails with elongated bearing tracks, one rail mounted to the component and the other to the frame and with the tracks aligned along the direction of component movement. An elongated metal bar, preferably of brass or oil impregnated bronze is slidably mounted in the bearing tracks to slidably support the driven component. A ball nut assembly having a pair of high durometer rubber pads drivingly connects the stepping motor shaft to the driven component.An X-Y rectilinear drive apparatus includes an upper X and a lower Y drive stage.

Abstract: The present invention encompasses compounds I and II, mixtures of I and II and acid addition salts thereof wherein R is hydrogen or loweralkyl having 1-3 carbon atoms, as well as compounds wherein the phenol moiety is labeled with .sup.125 I or .sup.131 I. The radiolabeled compounds are useful in radiochemical assaying for folic acid.

Abstract: The present invention encompasses an improved method for detecting antigen or antibody bound to a solid support which involves the reaction of hapten-labeled antibody to the antigen or antibody to be detected followed by reaction of the hapten moiety with labeled antibody to the hapten and the determination of the amount of label bound to the solid support.

Abstract: The present invention encompasses a method for enumerating microbial cells in an aqueous test sample comprising: fluorescently labeling the microbial cells in test sample intermixing a known amount of monodispersed fluorescently labeled beads of about cell size into the test sample, and determining the ratio of bacterial cells to fluorescently labeled beads, the reagents for practicing this method. The methods and reagents of the present invention are particularly useful in counting bacterial cells in urine.

Abstract: The present invention comprises compounds of the formula ##STR1## and the biologically acceptable acid addition salts thereof, wherein R.sub.1 represents hydrogen or lower alkyl having 1 to 4 carbon atoms; R.sub.2 represents an alkylene having 2 to 4 carbon atoms; R.sub.3 represents amino or guanidino; R.sub.4 represents nitrophenyl, methylnitrophenyl, dinitropheyl, naphthyl, or nitronaphtyl; m is 2 or 3; and n is 3 or 4. The compounds of the present invention are analytical reagents useful for measuring proteolytic enzymes such as thrombin and trypsin. The enzymatic hydrolysis of the invention compounds provides a chromogenic amine by which the proteolytic enzyme concentration can be determined spectrophotometrically.

Abstract: A bimodal automatic lens focussing apparatus including detection and switching means for detecting a loss in a localized focal condition and switching to a search mode wherein the objective lens is scanned between its outer limits to reacquire focus. Photodiode arrays sense respective light images on either side of the desired focal plane, and the resulting signals are processed to drive the lens to the desired focal plane. A level discriminator monitors the processed signals. Upon detection of a loss of the localized focus condition a mode switch is gated to couple a ramp generator to the lens driver. The lens is scanned between its outer limits until the level discriminator again detects the localized focus condition and the ramp generator is decoupled from the lens driver.