Abstract: A recombinant DNA construct, useful for obtaining excretion from E. coli of a heterologous protein, comprises a coding region in which DNA coding for the heterologous protein in coupled in reading frame with DNA coding for the OmpA signal peptide, to enable secretion of the protein into the periplasm; and a control region linked operably with the coding region to enable expression thereof in an E. coli host, wherein the control region comprises the tac promoter, the lac operator and a consensus ribosome binding site. With this construct, the excretion of heterologous proteins from E. coli can be achieved, consistently and for a wide variety of such proteins, without assistance from carrier proteins or membrane-lytic agent and by using "healthy" hosts rather than mutant strains having defective outer membranes.

Abstract: Methylxanthines such as caffeine are removed from aqueous solution by contact with cyclodextrin. A decaffeination process using selected cyclodextrin species is particularly disclosed.

Abstract: The invention relates to a device and method for performing qualitative enzyme immunoassays. The device comprises at least one tube having antibody, antigen or hapten attached to an internal surface thereof. A first syringe is connectable to a first end of the tube or tubes and supplies a flow of test liquid therethrough. A second syringe having a two piston arrangement is connected to the tube so as to allow a first wash solution followed by an enzyme conjugate solution to be flowed therethrough. Finally a third syringe, also having a two piston configuration, is connected to the tube so as to allow a second wash solution followed by an enzyme substrate and metabolite indicator solution to be flowed therethrough.

Abstract: Alkaloid dimers are formed by coupling vindoline and catharanthine in the presence of ferric ion. The predominant products are 3',4'-anhydrovinblastine and vinblastine when reaction conditions are selected appropriately.

Abstract: A device for performing a plurality of immunochemical assays simultaneously comprises a waste reservoir about which are positioned at least two assay tubes connected in series by conduits formed in the base and top of the reservoir structure. A compound syringe is insertable into an opening formed through the top of the waste reservoir, the syringe being held in place by a receiving structure formed in the base of the reservoir and connected to the entrance end of the series of assay tubes. The various compartments of the compound syringe are emptied in sequence to cause the flow of sample and assay reagents to flow through the assay tubes. The device is structured to allow for the reflow of sample through the tubes if desired.

Abstract: An enzyme immunoassay device comprises a disk having a thin flexible membrane applied to one side thereof, the membrane defining a conduit and a plurality of reagent reservoirs. The reservoirs are isolated from one another or from the conduit by frangible seals. An assay tube having an assay reagent bonded to the inner wall thereof is attached to the exit end of the conduit. Means are provided for injecting a test sample into the conduit for flowing thereof through the assay tube. Means are also provided for forcing the contents of each reservoir through the conduit and assay tube in the desired order by causing the rupture of each frangible seal sequentially.

Abstract: The invention relates to a device and method for performing qualitative enzyme immunoassays. The device comprises at least one tube having antibody, antigen or hapten attached to an internal surface thereof. A first syringe is connectable to a first end of the tube or tubes and supplies a flow of test liquid therethrough. A second syringe having a two piston arrangement is connected to the tube so as to allow a first wash solution followed by an enzyme conjugate solution to be flowed therethrough. Finally a third syringe, also having a two piston configuration, is connected to the tube so as to allow a second wash solution followed by an enzyme substrate and metabolite indicator solution to be flowed therethrough.

Abstract: The invention provides a device for performing chemical or immunochemical assays quickly and on site. The device comprises a plastic molded body which may be miniaturized. The device is provided with a plurality of tubes for containing assay reagents, a small bore tube in which the assay is carried out, a sample tube, and conduit and valve means from the various tubes to the assay tube. The device is insertable into a programmable apparatus which controls the flows of the various reagents through the assay tube by means of plungers acting on pistons located in each reagent tube.