Abstract: A fuel filtration system and methods controlling, and operating a fuel filtration system. A first fuel filter head is fluidly coupled to one or more first fuel filters, a second fuel filter head is fluidly coupled to one or more second fuel filters and a selector valve is coupled to the first fuel filter head and the second fuel filter head. The selector valve includes a primary valve inlet port, a primary valve outlet port, and a movable valve body movable from a first position to a second position. The first position fluidly couples the first fuel filter head to the primary valve outlet port and fluidly decouples the second fuel filter head from the primary valve outlet port. The second position fluidly couples the second fuel filter head to the primary valve outlet port and fluidly decouples the first fuel filter head from the primary valve outlet port.

Abstract: A solution is described for preserving cells and/or extra-cellular components in naturally expressed bodily fluids (e.g. saliva, sputum, urine) for further downstream analysis and/or for diagnosis of a medical condition. The solution may be hypertonic with respect to blood. Techniques are described for enriching cells from a sample of a naturally expressed bodily fluid, and/or for analysis, e.g. to diagnose medical conditions such as cancer, obesity, infections, autism, Alzheimer disease, hetotological disorders, cardiovascular disease or disorders, diabetes, vulnerable plack, LTBI, HIV infection, COPD, ACQS.

Abstract: Disclosed herein is an improvement in a method for distinguishing cells in a biological sample by staining with a dye, wherein the improvement comprises employing as the dye a compound of the formula ##STR1## wherein G is O or S;R.sup.1, R.sup.3, and R.sup.5 are independently selected from the group consisting of hydrogen, alkyl, aryl, aralkyl, amino, styryl, bis(diaryl)vinylene, and ##STR2## wherein R is hydrogen or alkyl;Z represents the elements necessary to complete a basic heterocyclic ring system of the type used in cyanine dyes;n is 0 or 1;R.sup.2 is hydrogen or, taken together with either R.sup.1 or R.sup.3, represents the elements needed to complete an aromatic or a carbocyclic ring system;R.sup.4 is hydrogen or, taken together with either R.sup.3 or R.sup.5, represents the elements needed to complete an aromatic or a carbocyclic ring system; andX.sup.- is an anion.

Abstract: Disclosed herein is an improvement in a method for distinguishing cells in a biological sample by staining with a dye, wherein the improvement comprises employing as the dye a compound of the formula ##STR1## wherein G is O or S;R.sup.1, R.sup.3, and R.sup.5 are independently selected from the group consisting of hydrogen, alkyl, aryl, aralkyl, amino, styryl, bis(diaryl)vinylene, and ##STR2## wherein R is hydrogen or alkyl;Z represents the elements necessary to complete a basic heterocyclic ring system of the type used in cyanine dyes;n is 0 or 1;R.sup.2 is hydrogen or, taken together with either R.sup.1 or R.sup.3, represents the elements needed to complete an aromatic or a carbocyclic ring system;R.sup.4 is hydrogen or, taken together with either R.sup.3 or R.sup.5, represents the elements needed to complete an aromatic or a carbocyclic ring system; andX.sup.- is an anion.

Abstract: An element for the analysis or transport of liquid, especially aqueous liquids, contains a structure comprising a plurality of heat-stable, organo-polymeric particles non-swellable in and impermeable to the liquid, and an adhesive concentrated at particle surface areas contiguous to adjacent particles bonding the particles into a coherent, three-dimensional lattice that is non-swellable in the liquid. A substantial portion of the particle surface area in this lattice structure is therefore effectively free from adhesive. The lattice structure has interconnected void spaces among the particles representing a total void volume of about 25 to 80 percent to provide for transport of the liquid. The adhesive comprises an organic polymer different from that of the particles and insoluble in the liquid under analysis. The amount of adhesive in the structure is less than 10 weight percent of the particles.

Abstract: An element for the analysis or transport of liquid, especially aqueous liquids, contains a structure comprising a plurality of heat-stable, organo-polymeric particles non-swellable in and impermeable to the liquid, and an adhesive concentrated at particle surface areas contiguous to adjacent particles bonding the particles into a coherent, three-dimensional lattice that is non-swellable in the liquid. A substantial portion of the particle surface area in this lattice structure is therefore effectively free from adhesive. The lattice structure has interconnected void spaces among the particles representing a total void volume of about 25 to 80 percent to provide for transport of the liquid. The adhesive comprises an organic polymer different from that of the particles and insoluble in the liquid under analysis. The amount of adhesive in the structure is less than 10 weight percent of the particles.

Abstract: There are described stabilized fluorescent labels comprising rare earth chelate incorporated in polymeric beads derived from a latex. Labeled reactive proteinaceous species such as labeled immunoreagents comprising the stabilized fluorescent labels having portein adsorbed or covalently bonded thereto are also described.

Abstract: A new peroxidase assay for substances demonstrating peroxidative activity is described which is based on the peroxidase catalyzed oxidation of dichlorofluorescin to dichlorofluorescein by peroxide. The dichlorofluorescin is formed from diacetyldichlorofluorescin either by the direct addition of peroxide or by the inclusion of a peroxide generating system (e.g., glucose plus glucose oxidase or uric acid and uricase) in the reaction mixture. As long as all reactants other than the peroxidase are present in excess, the rate of fluorescence increase is linearly related to the amount of peroxidase in the sample under assay.

Abstract: There are described stabilized fluorescent labels comprising rare earth chelate incorporated in polymeric beads derived from a latex. Labeled reactive proteinaceous species such as labeled immunoreagents comprising the stabilized fluorescent labels having protein absorbed or covalently bonded thereto are also described.

Abstract: An element for the analysis or transport of liquid, especially aqueous liquids, contains a structure comprising a plurality of heat-stable, organo-polymeric particles non-swellable in and impermeable to the liquid, and an adhesive concentrated at particle surface areas contiguous to adjacent particles bonding the particles into a coherent, three-dimensional lattice that is non-swellable in the liquid. A substantial portion of the particle surface area in this lattice structure is therefore effectively free from adhesive. The lattice structure has interconnected void spaces among the particles representing a total void volume of about 25 to 80 percent to provide for transport of the liquid. The adhesive comprises an organic polymer different from that of the particles and insoluble in the liquid under analysis. The amount of adhesive in the structure is less than 10 weight percent of the particles.

Abstract: Methods, compositions and elements for detecting a nitrogen-containing compound capable of releasing ammonia upon enzymatic action are described. The method comprises contacting in an aqueous medium a sample suspected of containing such a compound and a novel assay composition comprising at least one enzyme which catalyzes the decomposition of the compound to ammonia and detecting the ammonia by condensation with a .beta.-diketone in the presence of an aldehyde, preferably formaldehyde, and measuring the color or fluorescence produced by any resulting dihydropyridine. According to a preferred embodiment, the aldehyde is generated in situ and the .beta.-diketone is polymeric.The foregoing assay composition can be incorporated into single-layer or multilayer analytical elements of the type known in the prior art. A preferred such element comprises an isotropically porous spreading layer in fluid contact with a reagent layer. The spreading layer is most preferably non-fibrous.