Abstract: Methods are disclosed for conducting assays. One such method comprises providing in combination a first bibulous member zone ("first zone") and a liquid medium containing a component. The first zone has non-diffusively bound thereto a reagent interreactive with the component. Conditions are selected wherein the liquid medium and at least a portion of the component contained therein traverse all of the first zone and migrate by capillary migration into a second bibulous member zone ("second zone"). The second zone is of a different composition than the first zone and is incapable of specifically binding the component except when an analyte is to be detected and the method further includes causing a reagent to become bound to the first bibulous member zone in relation to the amount of analyte present.

Abstract: Samples of a petroleum oil stream (e.g. crude oil feed stream to a refinery) are continually monitored to determine incompatible asphaltenes therein and the rate of antifoulant is adjusted in response to changes in the level of incompatible asphaltenes. The method of the present invention employs thin layer chromatographic films for separating incompatible asphaltenes and for measuring an optical property indicative of the incompatible asphaltenes, and for varying antifoulant addition in response to changes of the optical property measured.

Abstract: A method for purifying two distinct insulin mediators to substantial homogeneity, and relative purity values above 80%, comprises adsorption on first anion exchange resin and subsequently on a chelex cation exchange resin column. The chelex resin ion exchange column substantially increases the activity of the recovered mediator. Following purification, the already treated fraction is subjected to three successive thin layer chromatography purification steps, the last giving, in the presence of ninhydrin stain, a characteristic salmon-color spot, which is indicative of the presence of the mediator. This process can also be used as a screening process, the absence of the salmon-colored spot being indicative of the diabetic state. Structure information on the insulin mediators obtained is given.

Abstract: The present invention relates to a process for the visualization of substance stains on dry layer chromatograms without further addition of a mobile phase, which device has foil of at least one layer and comprises one or more reagents for the visualization of substance stains.

Abstract: A chemical analysis method for indirect detection thin layer chromatography of cations that provides a rapid indication of the amount and type of cation present with minimal equipment requirements. The method includes four steps. The first step is to equilibrate a thin layer cation exchange chromatography plate with a color-forming cation, such as with copper II, to form a prepared plate. The second step is to deposit a sample on the prepared plate to form a spotted plate, the sample containing a cation of interest, such as sodium I. The third step is to develop the spotted plate with a liquid solution containing the color-forming cation, such as a solution of copper II ions, to chromatograph the cation of the sample to form a developed plate.

Abstract: Improved chromatographic strip binding assay devices are provided for determining the presence or amount of an analyte present in a patient sample. Assay label reagents interact with capture reagents immobilized in a testing region on the strip substrate to generate a visually detectable image indicative of the test result. The test result images include a minus sign (-) to indicate a negative test result for analyte which image is generated if the suspect analyte is absent in the patient sample and a plus sign (+) to indicate a positive test result for analyte which image is generated if the suspect analyte is present or is present at a pre-determined concentration in the patient sample. The immobilized capture reagents responsible for the location and configuration of the test result images are applied to the strip at an angled orientation with respect to the fluid flow direction of the strip to ensure that sharp substantially complete test result images are formed during performance of the assay.

Abstract: A method and apparatus for the quantitative determination of an analyte in a liquid employs a liquid-permeable solid medium defining a liquid flow path. The medium includes a number of reaction-containing reaction zones spaced apart along the flow path and in which reaction occurs with the analyte or an analyte derivative (e.g., a labeled analyte) to result in the formation of a predetermined product. Detector means are employed to detect analyte, analyte derivatives, reactant or predetermined product in the reaction zones, the number of such zones in which such detection occurs indicating the amount of analyte in the liquid.

Abstract: A method for distinguishing an alcoholic person from non-alocholic persons which comprises measuring the potential of lymphocytes from that person to produce phosphatidylenthanol and comparing the results obtained with a standard obtained from the lymphocytes of persons which are known not to be at substantial risk of becoming alcohol dependent which lymphocytes were incubated under identical conditions.

Abstract: A method for determining the presence of an analyte in a fluid is described along with various components of an apparatus specifically designed to carry out the method. The method involves taking a reflectance reading from one surface of an inert porous matrix impregnated with a reagent that will interact with the analyte to produce a light-absorbing reaction product when the fluid being analyzed is applied to another surface and migrates through the matrix to the surface being read. Reflectance measurements are made at two separate wavelengths in order to eliminate interferences, and a timing circuit is triggered by an initial decrease in reflectance by the wetting of the surface whose reflectance is being measured by the fluid which passes through the inert matrix. The method and apparatus are particularly suitable for the measurement of glucose levels in blood without requiring separation of red blood cells from serum or plasma.

Abstract: An improved Schirmer I Tear Test is provided. The improvement comprises a strip having a graduated migration scale printed on the test strip and the presence of a water soluble marker dye that comigrates with the tear migration front. Both improvements serve to increase the reproducibility of the test and ease which with the results are read.

Abstract: A chromatographic device is disclosed. The device comprises in combination a housing, a strip of bibulous material non-removably confined in the housing. The strip has a length and width only slightly less than the length and width of the inner walls of the housing. The inner walls of the housing have means attached thereto for supportively confining the strip in the housing. The strip is confined so that (1) the front and back of the strip are essentially free from contact with the walls of the housing and (2) the capillary action of the strip remains substantially unchanged, and (3), where the strip is paper, the strip is allowed to expand as it is traversed by the liquid medium. The bottom end of the housing contains means for enabling contact of a portion of the strip with the liquid medium. The housing further contains means for visually observing the strip and can also contain indicating means cooperative therewith to assist in determining the result of a chromatographic test.

Abstract: An apparatus and method for performing enzyme-linked immunological sandwich assays (ELISA) by affinity chromatography. Formation of the antibody-antigen-conjugate complex, and the development of a chromatophore indicator take place in a semi-automated, walk-away, fashion. The immunoassay apparatus comprises a chromatography tank, which further comprises a reaction compartment and a plurality of liquid solvent reservoirs, with a first-liquid reservoir being configured higher than a second-liquid reservoir. The apparatus allows automatic sequential and discrete movement of wash solution, followed by a color development solution, with unbound conjugate being substantially washed away from the immunological sandwich complex before the color development solution automatically comes into contact with the immunological complex.

Abstract: A test strip for analysis of analytes such as antigens, antibodies or polynucleotides employs a chromatographic medium and a solvent capable of transporting reagents and/or sample. Reagents are selected and disposed on the medium such that a labeled (first) reagent arrives at the detection (third) zone only after analyte is immobilized there and non-reactive sample componets have been transported beyond the detection zone. This sequential arrival is accomplished by the relative mobility of the reagent or sample; or by the site relationship of the zones. Preferably, the site relationship of the sample (second) zone and the label (first) zone is such that a plurality of pathways guide the sample and labeled reagent and any subsequent reagents to the detection zone in the recited order. Single and multiple pathway devices are disclosed.

Abstract: The present invention relates to improved specific binding assay devices comprising a chromatographic medium including a reaction site at which a specific binding reagent is immobilized, a sample application well located adjacent to the chromatographic medium and offset upstream from the reaction site, and a liquid absorption blotter offset downstream from the reaction site.

Abstract: A process for preparing a baseoil blend of predetermined coking tendency, and for measuring the effectiveness of additives for reducing coking tendency in baseoils, utilizing the relationship of the content of volatile fractions and how boiling fractions in baseoil to the onset and/or progression of asphaltene formation.

Abstract: A method for the qualitative assessment of oxidative drug metabolism deficiencies, preferably for the qualitative assessment of dextromethorphan metabolism, in a subject comprises analyzing a sample fluid from the subject, for example urine, which contains metabolites of a probe drug using high performance thin layer chromatography.

Abstract: Apparatus and method of sequencing nucleic acid molecules, including DNA and RNA molecules. Several copies of the molecules are labeled with a radioactive tracer and divided into separate groups. The groups of molecules are then each chemically cleaved to produce labeled fragments of varying length which terminate in predetermined bases. The groups of fragments are then introduced into separate columns of electrophoresis gel and voltage is applied across the gel to cause subgroups of the fragments to propagate along the columns at a velocity which is a function of the length of the fragments in the subgroup. Radiation detectors are used to detect the subgroups of fragments as they pass a predetermined position along the gel column, and data corresponding to the order in which the subgroups of fragments are detected is stored in a memory. Such data is then used to determine the bases sequence of the molecules.

Abstract: A colored compound containing a cationic group and a cellulose reactive group, especially a compound of the formula:A--Y--B IY'--B IIwhereinA is the cationic group;Y is a chromophore;Y' is a cationic chromophoreandB is the reactive group, which is suitable for the preparation of a protein adsorbent or precipitant for use in the separation of mixtures of proteins.

Abstract: A thin-layer rod for thin-layer chromatography conducted by the use of a flame ionization detector, comprising a rodlike support and a stationary phase made of an adsorbent which is superposed on the rod-like support, with chemical modification made in at least part of the stationary phase.

Abstract: A chromatography sample transfer process is disclosed in which fractions on a TLC plate are automatically moved by capillary action from the plate to separate receptacles adapted to retain material for diffuse reflectance measurement. The developed TLC plate is so mounted that its fractions are horizontally spaced, and its lower edge is in a solvent. As the solvent moves upwardly due to capillarity, it dissolves the fraction samples, and transfers them to a plurality of horizontally spaced wicks. The wicks, which are preferably made of sintered stainless steel powder, carry their solvent/sample material upwardly to separate receptacles, each containing transparent powder which retains the sample during diffuse reflectance measurement. The solvent is removed from the receptacles by horizontal airflow (air knife) without requiring significant heating.

Abstract: Apparatus and method for determining the tendency of hydrocarbon liquid to foul equipment includes a horizontal polymeric membrane made from polymers containing polar atoms, a light source for scanning hydrocarbon liquid sample on the membrane, and means for measuring the difference in light reflected by the asphaltene ring and the membrane matrix. Energy sources other than light may be employed.

Abstract: Apparatus and method for determining the tendency of hydrocarbon liquid to foul equipment includes a horizontal TLC plate, a light source for scanning hydrocarbon liquid sample on the TLC plate, and means for measuring the difference in light reflected by the asphaltene ring and the TLC matrix. Energy sources other than light may be employed.

Abstract: A device is disclosed for use in a chromatographic system wherein a component of a mixture is partitioned between a liquid phase and an immobile phase. The device comprises at least one strip of a bibulous material. In the chromatographic system the component traverses at least a portion of the strip. The strip generally has a longitudinal edge substantially corresponding to the direction of traverse of the component. The longitudinal edge has the characteristic of substantially the same rate of traversal by the component along this edge when compared to the rate of traversal of the component along the body of the strip. The strips are prepared from a sheet of a bibulous material by non-deformative or non-compressive cutting of the sheet. The preferred cutting means is a laser beam.

Abstract: A device is disclosed for use in a chromatographic system wherein a component of a mixture is paritioned between a liquid phase and an immobile phase. The device is comprised of a chromatographic material. In the chromatographic system the component traverses at least a portion of the chromatographic material. The device generally has at least one longitudinal edge substantially corresponding to the direction of traverse of the component. The longitudinal edge includes means for controlling the shape of the front of the traversing component.

Abstract: A method for determining the fouling tendency of an asphaltene containing petroleum stream such as crude oil by the use of thin layer chromatography. The chromatogram of a crude oil formed in the presence of an asphaltene antisolvent which exhibits a fouling tendency developed a distinct, dark ring or disk.

Abstract: A method for determining the fouling tendency of an asphaltene containing hydrocarbon stream such as crude oil by the use of thin layer chromatography. The chromatogram of a crude oil exhibiting a fouling tendency developed a distinct, dark ring or disk.

Abstract: A test paper which is disclosed herein comprises a filter paper bearing a mixed berberine sulfate/pigment solution applied on a part thereof. The mixed berberine sulfate/pigment solution is produced by dissolving berberine sulfate and a pigment in a solvent such as water or an organic solvent. The test paper is used to determine the concentration of common salt in an aqueous common salt containing solution of urine or food as well as the content of chlorine or other halogen ions such as bromine and iodine ions in an aqueous halogen-containing solution. The test paper may be made by dissolving a berberine sulfate and a pigment in a solvent and applying the resulting mixed berberine/pigment solution onto a portion of a filter paper. The pigment may be Patent Blue V.

Abstract: New separation materials for thin layer chromatography are based on carrier materials coated with an adsorbent silica gel layer which has been surface-modified by a silanizing agent after the coating step. The degree of covering of the modifying reagent can be adjusted in a defined and controllable manner, e.g., from 0.15 to 0.8 .mu.mol/m.sup.2 in the case of reversed phase materials and 1.2 to 2.5 .mu.mil/m.sup.2 in the case of hydrophilic materials. A process for the preparation of these separation materials is also provided.

Abstract: A method of forming analyzable adducts in a mixture of compounds by contacting the mixture with a boron reagent having the formula of either ##STR1## where each X and Y is, independently, an alkyl group of 12 or fewer carbons or an aryl group of 6-20 carbons; or BZ.sub.3, where each Z is, independently, an alkyl group of 12 or fewer carbons, or an aryl group of 6-20 carbons.

Abstract: A method for rapidly transferring chromatography or adsorption column eluates in a continuous flow directly to the chromatography plate for continuous evaporation of the solvents at a rate compatible with the flow.

Abstract: A device is disclosed for collecting a liquid sample and diluting the liquid sample by virtue of being adapted for use with a container having a volume of diluting liquid. The device comprises a housing adapted for mating with the container where the mated housing and container form a chamber. A bibulous pad is attached to the housing for collecting a predetermined amount of a liquid sample. Additionally, the device, when used with the container, creates a pressure differential between the interior of the housing and the chamber. The pressure differential is sufficient to move a predetermined volume of the diluting liquid through the bibulous pad and into the housing. The device can be used for assaying for a component of a sample. The device has particular use in immunochromatography and for convenience can also contain a strip of bibulous material confined in the housing.

Abstract: Thin-layer chromatography is employed to separate enantiomers of the general formula, ##STR1## in which C* represents an asymmetric center and the substituents R.sup.1, R.sup.2, and R.sup.3 are such that they supply the structural element ##STR2## for .alpha.-amino- or .alpha.-iminocarboxylic acids, particularly the well-known .alpha.-amino- or .alpha.-iminocarboxylic or for derivatives of such carboxylic acids, either of which contains no free thiol groups. In the thin-layer chromatographic separation operation a TLC plate is used which is coated with silica gel hydrophobicized by a silane derivative and which is further impregnated with an ionic compound of a divalent transition metal and a chiral selector. The mobile phase employed is a ternary mixture of a water-miscible alkanol, such as methanol, water, and acetonitrile, or a quaternary mixture of the latter ternary mixture to which a water-miscible cyclic ether, such as tetrahydrofuran, has been added.

Abstract: A chromatographic plate comprising a support having a plurality of linear grooves engraved on the rear is disclosed. Each of said grooves have a uniform depth of a half or less as large as the thickness of the support and serves to guide a cutter. After the chromatographic development, the support may easily be cloven along the grooves into strips together with an adsorbent layer carried by the front of the support to give a sample holder for mass spectrometry.

Abstract: Sampling and analyzing at least one mixture of substances by slab chromatography or thin layer chromatography involves sampling the mixture on a non-adsorbent solid support using a sampling member to achieve precisely repeatable conditions, depositing an appropriate amount of the mixture to be analyzed on an edge zone of a chromatography plate, bringing the said edge of the chromatography plate into contact with a solvent or a mixture of solvents to cause the migration of the mixture on the chromatography plate and the separation of the constituents of the said mixture, and developing the said plate for the qualitative and/or quantitative analysis of the constituents of the mixture, by pressing that face of the support which bears the mixture against the chromatography plate until the mixture to be analyzed has essentially migrated entirely out of the abovementioned support.

Abstract: Chromatographic immunoassay employing a specific binding pair member and a label conjugate which delineates a border whose distance from one end of the chromatograph relates to the amount of analyte present. By combining the label conjugate and sample in a solution and immunochromatographing the solution, or employing a combination of enzymes, one enzyme being the label and the other enzyme affixed to the chromatographic support, the position of the border defined by the label can be related to the amount of analyte in the sample solution.Preferably, an immunochromatograph is employed having both a specific binding pair member and an enzyme affixed to the support.

Abstract: A colorimetric indicator in sheet form comprising an indicator substance, a high surface area carrier for said indicator substance, and a self-adhering clay mineral binder coated on a backing is disclosed. The colorimetric indicator is useful for personal monitors, as end of service life indicators for respirators, thin layer chromatography plates, and vapor transfer sheets.

Abstract: A method and apparatus for continuous extraction of an ingredient from a sample employs a container having a solvent therein selected for its ability to extract the ingredient. The sample is held against a porous substrate having a lower portion which is located below the sample and placed in the solvent, and an upper portion which is located above the sample and exposed to a selected atmosphere. In a continuous supply from the container, solvent is caused to ascend the substrate by capillary action, penetrate the sample, extract the ingredient therefrom, and continue to ascend the upper portion of the substrate where it evaporates, depositing the extracted ingredient thereon. The upper portion of the substrate containing the ingredient may then be removed.