US3689364A - Sensitive color indicators for lipase determinations - Google Patents

Sensitive color indicators for lipase determinations Download PDF

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US3689364A
US3689364A US858154A US85815469A US3689364A US 3689364 A US3689364 A US 3689364A US 858154 A US858154 A US 858154A US 85815469 A US85815469 A US 85815469A US 3689364 A US3689364 A US 3689364A
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emulsion
lipase
color
reagent
indicator
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Arnold Hartel
Roland Helger
Hermann Lang
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Merck Patent GmbH
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Merck Patent GmbH
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    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
    • C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
    • C12Q1/34—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving hydrolase
    • C12Q1/44—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving hydrolase involving esterase

Definitions

  • the titration of liberated fatty acid is facilitated by employing one or more indicators of the group m-cresol purple, p-xylenolsulfonephthalein, dibromothymolsulfonephthalein, thymolsulfonephthalein and a-naphtholphthalein.
  • This invention relates to a method of analyzing body fluids for the presence of lipases and to improved color indicator compositions for this purpose.
  • Lipases are enzymes which split fats and oils into glycerides and fatty acids. They are widely prevalent in the animal organism, with particularly high concentrations being found in the liver and in the secretion of the pancreas digesting the nutritive fats in the small intestine. When the pancreas is diseased, lipase enters the bloodstream. For this reason, the determination of lipase in the serum is an important diagnostic tool for the recognition of pancreatic diseases.
  • the lipase was generally determined by providing an excess of a lipase substrate and measuring the amount of fatty acid produced by the lipase. This measurement was accomplished by titration with an alkali, using an indicator, or by the extraction of copper salts.
  • the specific indicators employed for the titrations were thymolphthalein and phenolphthalein, respectively (Deutsche Medizinische Stammier], vol. 90, p. 1170 (1965) and Analytical Biochemistry, vol. 6, p. 451 [1963]).
  • As the substrate an oil-in-water emulsion was generally employed.
  • esterase determination instead, i.e., a soluble ester of lower chain length is employed as the substrate, which ester though well-defined, is hydrolyzed not only by the lipase but also by other esterases contained in the serum (cf. Aerloises Labor [Medical Laboratory], vol. 13, 157 [1967]).
  • the use of such a soluble ester is feasible in the lipase determination in enriched enzyme preparations, but not in the serum, since the lipase concentration in the serum is very slow (normal range up to 0.1 u/ml.), and the significant concentrations of several other esterases obscure the results. Accordingly, heretofore, for the determination of the socalled genuine lipase there was no choice but to employ the above-mentioned slow and expensive methods.
  • a principal object of this invention is to provide an improved means for a lipase determination based on an oil/water emulsion substrate.
  • compositions for the determination of lipase in body fluids comprising an aqueous fatty or oily emulsion and a pH color indicator, the improvement being that, as the color indicator, there is employed m-cresol purple and/ or p-xylenolsulfonephthalein and/ or dibromothymolsulfonephthalein and/or thymolsulfonephthalein (thymol blue) and/or a-naphtholphthalein.
  • the invention also is directed to reagent combinations and processes for using same, especially for the detection of abnormal amounts of lipase in serum.
  • m-cresol purple and pxylenolsulfonephthalein are preferred.
  • the indicators exhibit an abrupt color change, for example, m-cresol purple from violet to yellow, and p-xylenolsulfonephthalein from blue to yellow.
  • the pH of the solution is suitably adjusted so that the color change occurs by the addition of a minimal amount of acid.
  • m-cresol purple a brown-tinged purple shade is set, and when using p-xylenolsulfonephthalein, the solution is adjusted to a browntinged blue shade.
  • the adjustment to the desired pH is advantageously carried out by adding to the emulsion an alkaline solution of the indicator, for example a solution of m-cresol purple or p-Xylenolsulfonephthalein in a dilute, e.g. 0.1 N, sodium hydroxide solution, and thereafter adding an acid, for example dilute hydrochloric acid or another dilute mineral acid, until the desired color shade is obtained.
  • an alkaline solution of the indicator for example a solution of m-cresol purple or p-Xylenolsulfonephthalein in a dilute, e.g. 0.1 N, sodium hydroxide solution
  • an acid for example dilute hydrochloric acid or another dilute mineral acid
  • the agent is stored for a longer period of time prior to the lipase determination, it is advisable, in order to prolong the shelf life, to add the indicator only shortly before use to the emulsion.
  • the emulsion is at first prepared (without the indicator) with a preferably neutral or only weakly alkaline or weakly acidic pH, and separately therefrom, an alkaline indicator solution is produced. Both solutions show a very good shelf life even over extended periods of time.
  • the indicator is employed in the ready-to-use emulsion in a concentration of generally about 0.001-1%, preferably 0.05-0.2%, based on the weight of the entire emulsion.
  • the reagent of this invention contain only one of the above-disclosed compounds (m-cresol purple, p-xylenolsulfonephthalein, dibromothymolsulfonephthalein, thymolsulfonephthalein or a-naphtholphthalein).
  • the indicator can also be comprised of a mixture of 2 or more of these compounds.
  • it can be advantageous in some cases to employ, in addition to a main indicator, e.g. m-cresol purple or p-xylenol blue, another of said indicators in a low concentration, in order to adjust the hue of the reagent of this invention to that desired for the changeover range.
  • Such as adjustment may be necessary, for example, when it is desired to shift the hue of the main indicator so as to have a better comparison with a printed color scale.
  • a minor amount of ix-naphtholphthalein, which is blue in the alkaline range to a compound employed as the main component of the color indicator, such as m-cresol purple or p-xylenosulfonephthalein, the color hue of the reagent in the alkaline range can be, in total, shifted to blue.
  • Such color shifts of the reagent of this invention can also be obtained by the addition of small amounts of other color indicators than those mentioned above, for example by the addition of diphenol purple (red shift, especially in the neutral range, when employing m-cresol purple as the main component of the color indicator) or in some cases also by the addition of small amounts of another color compound, such as carotene, by means of which a yellow hue is obtained.
  • these compounds are added, for example, in a concentration of up to 0.05% (based on the emulsion).
  • the reagent of this invention contains any natural or synthetic fatty acid ester, particularly fatty acid glycerol esters.
  • fatty acid glycerol esters particularly fatty acid glycerol esters.
  • triglycerides or optionally also diglycerides of fatty acids such as palmitic, stearic, oleic, linoleic or lauric acid.
  • natural oils and fats for example coconut oil
  • Particularly preferred is olive oil. It is advantageous to remove any free fatty acids from the oils and fats before the latter are used as the lipase substrate, for example by purifying the oil or fat by chromatography over a basic adsorbent, such as aluminum oxide.
  • the oils and fats can also be purified in a dilferent manner, or also hydrogenated.
  • hydrogenated colza oil is likewise suitable for use as the lipase substrate.
  • concentration range generally used in the reagent of this invention, is l to 30, preferably 10 to 25 parts by volume of lipase substrate to 99 to 70, preferably 90 to 75 parts of water. Particularly advantageous in a range of 20 parts by volume of lipase substrate to parts by volume of water.
  • the agent of the invention generally contains at least one emulsion stabilizer.
  • emulsion stabilizer particularly suitable proved to be compounds having a protective colloid efiect, particularly gum arabic.
  • polyvinylpyrrolidone can also be employed as the protective colloid.
  • emulsion stabilizers having a protective colloid effect, especially gum arabic are present in the emulsion in a concentration of about 05-30%, preferably 10-25% by Weight based on the weight of emulsion.
  • gum arabicum exerts an activating influence on the lipase.
  • ordinary emulsifiers for oil/ water or fat/water emulsions can also be employed in the reagent of this invention, for example, polyethylene glycol fatty alcohol ethers, especially also polyoxyethylene derivatives of sorbitol anhydrides, such as polyoxyethylene sorbitan oleates, palmitates, stearates, for example polyoxyethylene sorbitan monopalmitate, monooleate, monostearate or trioleate or tristearate, polyethylene glycol al'kyl phenol ethers, sulfonic acid salts or sulfuric acid esters, for example isopropyl-naphthalenesulfonic acid salts or cetyl-, stearylsul-furic acid esters.
  • concentration of these emulsifiers ranges, for example, up to 20%, preferably up to 1% by Weight based on the weight of emulsion.
  • salts of bile acids for example, alkali cholates, alkali deoxycholates, alkali taurocholates, alkali glycocholates, and other bile acid salts.
  • alkali cholates, alkali deoxycholates, alkali taurocholates, alkali glycocholates, and other bile acid salts are employed in a concentration of up to about 2%, particularly up to 0.5% by weight based on the weight of emulsion.
  • the emulsion can contain substances, for purposes of stabilization, which prevent settling, for example the montmorillonite gelling agents, particularly alkaline earth or quaternary ammonium salts of montmorillonite fatty acids.
  • the montmorillonite gelling agents particularly alkaline earth or quaternary ammonium salts of montmorillonite fatty acids.
  • the extremely finely divided magnesium mont-morillonites ordinarily used as emulsion stabilizers for oil-in-water systems, having a density of 2.4 g./cm. and a moisture content of about 6%, or a dimethyl dioctadecyl-ammonium montmorillonite having a density of 1.80 g./cm. and a moisture content of less than 3%.
  • These antisettling agents are employed in a concentration of up to about 3%, particularly up to 1%.
  • the use of antisettling agents of the type above described in the field of the lipase determining is novel.
  • the reagent of this invention can contain emulsion stabilizers which increase the viscosity of emulsions at low temperatures.
  • emulsion stabilizers which increase the viscosity of emulsions at low temperatures.
  • gel-forming, higher-molecular weight compounds are suitable, for example, which are not split by esterases.
  • agar proved to be suitable as an additive for increasing viscosity and thus for stabilizing the emulsion.
  • the application of agar in a reagent for the determination of lipase is novel.
  • the reagent of the present invention can also contain reducing compounds for preventing autoxidation and ensuing separation of the emulsion, preferred reducing agents being mercaptoethanol, cysteine, a-tocopherol acetate and/or ascorbyl palmitate in concentrations of up to about 1%, preferably up to 0.05% by Weight based on the emulsion.
  • reducing compounds for preventing autoxidation and ensuing separation of the emulsion
  • preferred reducing agents being mercaptoethanol, cysteine, a-tocopherol acetate and/or ascorbyl palmitate in concentrations of up to about 1%, preferably up to 0.05% by Weight based on the emulsion.
  • Tocopherol acetate and ascorbyl palmitate exhibit the advantage that they are soluble in fats and oils, respectively.
  • the described reducing compounds are applied by the reagent of this invention in the field of the lipase determination for the first time.
  • agents of the invention can also contain biostatic compounds (preservatives) for stabilizing the emulsion, which substances prevent microorganisms from attacking the substrate.
  • biostatic compounds preservatives
  • Suitable in this connection are, for example, organomercury compounds such as p-chloromercuribenzoate, phenylmercuric acetate, ethylmercurithiobenzo-3,4- oxazole-l-carboxylic acid or the sodium salt thereof, ethylmercurithiosalicylates, ethylmercurithiophenolsulfonic acids, p-hydroxybenzoic acid esters, particularly the methyl or ethyl or isopropyl ester, hexamethylenetetramine, iodoacetates and/or azides.
  • emulsion-stabilizing additive in the reagent of this invention, at least one compound from the classes of substances set forth above is used as the emulsion-stabilizing additive with gum arabic being preferred.
  • preservatives are used in the reagent of this invention together with gum arabic.
  • those emulsion stabilizers are particularly suitable which are not affected by esterases, particularly by esterases other than lipase, in a weakly alkaline range.
  • a solution of at least one emulsion stabilizer e.g. gum arabic
  • water is provided.
  • the emulsion is formed by the addition of the substrate, e.g. olive oil, under vigorous stirring.
  • the other additives employed for the agent for example additional emulsion-stabilizing, especially preservatives, can be admixed to the mixture either prior to or after the addition of the substrate.
  • the indicator can suitably be added to the emulsion in the form of a solution. In this way, the emulsion is obtained in a form ready to use. It is also possible to store the indicator separately from the emulsion in the form of a solution and add it to the emulsion just prior the lipase determination. This embodiment of the agent of the invention is preferred when a long shelf life is required.
  • the concentration of the indicator is suitably adjusted so that an aliquot portion (which can be measured in a simple manner, for example one drop of the indicator solution) is added to the oil/ water emulsion made ready beforehand, for example in the plastic cuvette, for purposes of one determination.
  • An oil/water emulsion containing theindicator can be stored for about 4 weeks, it being recommended to shake the emulsion before use.
  • the oil/water emulsion with the indicator is filled beforehand into a cuvette for one determination, it is advantageous to provide the contents of the cuvette with a film-forming coating.
  • This coating act like a cover and prevents the contents of the cuvette, at low temperatures and with the cuvette being stored upside down from solidifying underneath the seal of the cuvette opening; otherwise such solids would be forced out of the opening by a minor excess pressure produced in the cuvette.
  • This cover is advantageously formed as a layer on the emulsion by coating the latter with a liquid having little or no miscibility with water, i.e.
  • Preferred materials for the coating are solutions of natural, synthetic or semisynthetic polymers, e.g. a polyethylene derivative, such as polystyrene, polyvinyl acetate, polyvinyl chloride or polymethacrylates, or a cellulose derivative, for example a nitrated cellulose, such as collodion, or cellulose acetate, or epoxy lacquers or two-component urethane lacquers or urethane lacquers hardening under the effect of moisture, in readily evaporating organic solvents or solvent mixtures.
  • natural, synthetic or semisynthetic polymers e.g. a polyethylene derivative, such as polystyrene, polyvinyl acetate, polyvinyl chloride or polymethacrylates, or a cellulose derivative, for example a nitrated cellulose, such as collodion, or cellulose acetate, or epoxy lacquers or two-component urethane lacquers or urethane lacqu
  • ethers e.g. diethyl ether
  • lower alcohols such as ethanol
  • lower esters such as ethyl acetate
  • low-boiling hydrocarbons which, if desired, can also be substituted, for instance, by chlorine, such as diehloromethane, or ketones, such as, for example, acetone or cyclohexanone.
  • a plasticizer such as camphor, for example, can also be added.
  • the film-forming solid substances are preferably employed in each case in such a concentration that the thus-produced coating above the emulsion attains a thickness of up to 3 mm., preferably about 0.5 mm.
  • the reagent of this invention is combined with the lipase-containing sample to be examined, and the color change of the indicator incurred during the incubating time is evaluated.
  • a small metered volume preferably 0.1 ml., of the body fluid to be tested, for example serum or plasma, is introduced into a metered volume, for example 1 ml., of the ready-touse emulsion.
  • the mixture is thoroughly intermixed, as usual, and the color change is measured.
  • the color change can be measured by comparing the hue of the mixture with the corresponding hue on a calibrated color scale or on a calibrated color strip.
  • a calibrated color scale or a calibrated color strip used during the measurement can be produced as described in French Pat. 1,516,492.
  • the time interval for the incubation for example 1 hour is used as the basis.
  • the color change is determined by a comparison of the examined specimens with one another after the incubation period of, for example, one hour.
  • the hue of specimens having a normal lipase content-- which is almost unchanged after the incubation period is employed as the standard.
  • This maner of conducting the lipase determination according to the invention is especially suitable for series analyses, since in most cases over of the blood serums examined in the clinics exhibit a normal lipase content and thus can serve as the standard.
  • the few specimens showing a pathological increase in the lipase content can then be recognized by a hue which differs from the nearly unchanged color of the plurality of the examined specimens after the incubation period.
  • EXAMPLE 1 In a high speed mixer, 30 mg. of ethylmercurithiosalicylate and 90 mg. of gum arabic are added to 480 ml. of water. Thereafter, the mixture is adjusted to a pH of 10 by the addition of 2 N aqueous solution of sodium hydroxide. Thereupon, the mixture is subjected to centrifuging and the residue is filtered through a cotton swab in order to remove impurities. The filtrate is then mixed in a high speed mixer with 120 ml. of olive oil (purified over basic aluminum oxide) optionally with the addition of an emulsifier, for example a polyoxyethylene sorbitan oleate, palmitate or stearate.
  • an emulsifier for example a polyoxyethylene sorbitan oleate, palmitate or stearate.
  • reaction mixture is mixed for an additional 5 minutes and then blended with 600 mg. of m-cresol purple dissolved in 60 ml. of 0.1 N sodium hydroxide solution.
  • a dilute acid for example dilute hydrochloric acid
  • the pH of the mixture is adjusted to 8.8 (color: brown-tinged violet).
  • the thus-produced emulsion is either employed directly for the lipase determination or filled in 1 ml. batches into scalable plastic cuvettes.
  • the emulsion, in each plastic cuvette is provided with a layer of about 0.05 ml. of a 2% collodion solution. After the solvent has evaporated, a thin membrane is formed on the emulsion. Thereafter, the cuvettes are sealed, the contents of each plastic cuvete being suitable for one lipase determination.
  • EXAMPLE 2 An emulsion is prepared analogously to the technique described in Example 1, except that no indicator is added, and the pH is adjusted to 7.0. Separately from the emulsion, which is filled into cuvettes of 2 ml, are prepared: (1) a 1% solution of m-cresol purple in a 0.055 N sodium hydroxide solution; (2) a 0.02 N solution of sodium hydroxide; and (3) a 0.02 N solution of hydrochloride acid.
  • the 0.02 N sodium hydroxide or hydrochloric acid solution can be employed for regulating the pH of the emulsion altered after an extended period of storage.
  • the color of the emulsion is adjusted to a brown-tinged blue b the addition of dilute solution of sodium hydroxide or hydrochloric acid.
  • the resultant composition can be employed for the lipase determination as set forth in Example A.
  • EXAMPLE 4 Analogously to Example 3, an emulsion is prepared but without an indicator, the pH being adjusted to 7.0. Separate solutions are then prepared of: a 1% solution of p-xylenol blue in 0.055 N sodium hydroxide solution;- a 0.02 N solution of sodium hydroxide; and a 0.02 N hydrochloric acid solution.
  • EXAMPLE 5 23 g. of gum arabic 4 mg. of sodium ethylmercurithiosalicylate and 25 mg. of sodium azide are dissolved in 120 ml. of water.
  • This solution is introduced into a homogenizer, and during the operation of same, there is added a solution of 5 mg. of a-tocopherol acetate and 5 mg. of ascorbyl palmitate in 30 ml. of olive oil.
  • An indicator solution prepared by dissolving 1 g. of cresol purple, optionally together with mg. of
  • emulsion is mixed in a volume ratio of 1:10 with the above-described emulsion, so that, for example, 2 ml. of emulsion is mixed with 0.2 ml. of indicator solution.
  • the resultant lipase test reagent is employed in the same manner as the compositions of Example 14.
  • EXAMPLE 6 3 g. of gum arabic 20 ml. of sodium iodoacetate 1 g. of magnesium montmorillonite or dimethyl diocta-' decylammonium montrnorillonite and 0.5 g. of agar are dissolved or made into a slurr with 100 m1. of water.
  • the solution is homogenized in a mixer with 25 ml. of purified triolein.
  • One hundred parts by volume of the thus-prepared emulsion are mixed with one part by volume of a solution of 1 g. of cresol purple in 100 ml. of 0.05 N sodium hydroxide solution.
  • test reagent is employed analogously to the compositions of Examples 1-4.
  • EXAMPLE A 0.1 ml. of serum is introduced into the cuvette filled with 1 ml. of the emulsion prepared according to Example 1.
  • the mixture is shaken, and the resultant color hue is compared with a calibrated color scale.
  • the number associated with the color hue on the scale is read off, for example 150.
  • the specimen is allowed to stand for 1 hour at room temperature and, by comparison of the thusproduced color hue with the same color hue on the calibrated color scale, the number 350 is obtained.
  • the lipase content of the measured specimen is, in that case, 200 mu/ml.
  • the specimens After determining the initial color hue, are allowed to stand for 20 minutes at 37 C.
  • the thus-determined lipase content is the same as obtained in the above tests.
  • EXAMPLE B In a series test, 0.1 ml. of serum is mixed with 1 ml. of the emulsions produced in accordance with Examples 1 and 3, and then allowed to stand for 1 hour. In most of the specimens, the brownish-violet or brownish-blue color hue is hardly changed with respect to the initial color hue. The serums having a pathologically increased lipase content exhibit a brown to yellow or a dirty-green to yellow color. The exact lipase content in these pathological serums can then be determined exactly in accordance with Example .A.
  • EXAMPLE C 0.2 ml. of the indicator solution prepared according to Example 2 is added to 2 ml. of the emulsion of Example 2. Thereafter, the components are mixed, the pH indicator normally showing the desired color (brown tinged violet). When the pH' of the emulsion, for example due to extended storage periods, no longer exhibits the desired value, several drops of 0.02 N solution of sodium hydroxide or hydrochloric acid are added until the desired brown-tinged violet color hue is obtained.
  • a ready-to-use emulsion is prepared with the indicator of Example 4.
  • the correction of the pH of an emulsion stored for a longer period of time, necessary in some cases, is effected by the addition of the 0.02 N solution of sodium hydroxide or hydrochloric acid until a blue color hue is attained.
  • Serum 0.2 ml. is added to each of the ready-to-use emulsions, the mixture is shaken, and the lipase content is measured as described in Examples A and B.
  • a reagent combination suitable for direct colorimetric determination of serum lipase activity comprising:
  • a reagent combination according to claim 1 further including up to 2% by weight of a bile acid salt.
  • a reagent combination according to claim 1 further including a biostatic preservative.
  • a reagent combination according to claim 1 further including up to 3% by weight of an anti-settling agent.
  • a reagent composition according to claim 1 further including up to 1% by weight of a reducing agent selected from the group consisting of mercaptoethanol, cysteine, alphatocopherol acetate, ascorbyl palmitate, and mixtures thereof.
  • a reducing agent selected from the group consisting of mercaptoethanol, cysteine, alphatocopherol acetate, ascorbyl palmitate, and mixtures thereof.
  • a reagent composition according to claim 1 further including up to 0.05% by weight of a second color indicator to shift the color hue of said colorimetric indicator.
  • a reagent composition according to claim 11 wherein said second color indicator is alpha-naphtholphthalein, diphenol purple, or carotene.
  • a reagent composition according to claim 13 wherein the color thereof is adjusted to a brown-tinged shade, whereby a color change occurs upon the addition of a minimal amount of acid.
  • a reagent combination according to claim 1 further comprising a cuvette for containing said reagent combination and further provided with an insoluble film of a substantially water-immiscible film on the open surface of said emulsion, said film adhering to the sides of said cuvette for preventing movement of said emulsion to the top of said cuvette when said cuvette is stored upside down.
  • a method for the determination of serum lipase activity which comprises admixing a reagent composition according to claim 1 and a serum sample; incubating the reagent-serum mixture; and determining the lipase activity in correspondence with the resultant color of the incubated mixture.
  • said reagent composition includes up to 2% by weight of a bile acid salt.
  • said reagent composition includes up to 0.05% by weight of a second color indicator to shift the color hue of said colorimetric indicator.
  • A'method according to claim 15 wherein the color of said reagent composition is adjusted prior to the ad mixture thereof to a brown-tinged shade, whereby a color change occurs upon the subsequent addition of a minimal amount of acid.

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US858154A 1968-09-20 1969-09-15 Sensitive color indicators for lipase determinations Expired - Lifetime US3689364A (en)

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DE19681798285 DE1798285C3 (de) 1968-09-20 Neues Mittel und Verfahren zur Lipasebesti m mu ng
DE19691943454 DE1943454A1 (de) 1968-09-20 1969-08-27 Neues Mittel und Verfahren zur Lipascbestimmung

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JP (1) JPS5542703B1 (fr)
BE (1) BE738960A (fr)
CH (1) CH506792A (fr)
DE (1) DE1943454A1 (fr)
FR (1) FR2022180A1 (fr)
GB (1) GB1247449A (fr)
IL (1) IL32910A (fr)
NL (1) NL6913769A (fr)
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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3917515A (en) * 1974-03-13 1975-11-04 Jack M Goldberg Serum lipase method and medium
US4045290A (en) * 1975-02-28 1977-08-30 Princeton Biomedix Incorporated Diagnostic method and compounds for use therewith
WO1980002697A1 (fr) * 1979-06-04 1980-12-11 American Hospital Supply Corp Substrat de lipase
US4275151A (en) * 1977-02-03 1981-06-23 Eastman Kodak Company Hydrolysis of protein-bound cholesterol esters
US4275152A (en) * 1977-02-03 1981-06-23 Eastman Kodak Company Hydrolysis of protein-bound cholesterol esters
US4299917A (en) * 1979-02-14 1981-11-10 Boehringer Manneheim Gmbh Diagnostic agents for the detection of leukocytes in body fluids
US4331760A (en) * 1978-06-20 1982-05-25 Boehringer Mannheim Gmbh Diagnostic agent for the detection of leukocytes and chromogens useful therein
US4347313A (en) * 1978-02-27 1982-08-31 Boehringer Mannheim Gmbh Analytical determination of lipase
US4555483A (en) * 1982-08-11 1985-11-26 Eastman Kodak Company Methods, compositions and elements for the determination of lipase
US4988497A (en) * 1985-05-03 1991-01-29 Boehringer Mannheim Gmbh Process for the optical determination of lipase
EP1042500A1 (fr) * 1997-12-19 2000-10-11 NEN Life Science Products, Inc. Dosage enzymatique utilisant un substrat en phase solide

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1077498A (fr) * 1975-02-28 1980-05-13 George F. Bulbenko Monophosphates de bleu de thymol et sels derives
JPS6035117B2 (ja) * 1980-10-28 1985-08-13 富士写真フイルム株式会社 リパ−ゼ活性測定用試薬
TW442570B (en) * 1996-09-19 2001-06-23 Roche Diagnostics Gmbh Improved colour test for the detection of activity of lipase
CN100445731C (zh) * 2004-11-12 2008-12-24 中国科学院兰州化学物理研究所 半胱氨酸的比色检测分析方法

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3917515A (en) * 1974-03-13 1975-11-04 Jack M Goldberg Serum lipase method and medium
US4045290A (en) * 1975-02-28 1977-08-30 Princeton Biomedix Incorporated Diagnostic method and compounds for use therewith
US4275151A (en) * 1977-02-03 1981-06-23 Eastman Kodak Company Hydrolysis of protein-bound cholesterol esters
US4275152A (en) * 1977-02-03 1981-06-23 Eastman Kodak Company Hydrolysis of protein-bound cholesterol esters
US4347313A (en) * 1978-02-27 1982-08-31 Boehringer Mannheim Gmbh Analytical determination of lipase
US4331760A (en) * 1978-06-20 1982-05-25 Boehringer Mannheim Gmbh Diagnostic agent for the detection of leukocytes and chromogens useful therein
US4299917A (en) * 1979-02-14 1981-11-10 Boehringer Manneheim Gmbh Diagnostic agents for the detection of leukocytes in body fluids
WO1980002697A1 (fr) * 1979-06-04 1980-12-11 American Hospital Supply Corp Substrat de lipase
US4555483A (en) * 1982-08-11 1985-11-26 Eastman Kodak Company Methods, compositions and elements for the determination of lipase
US4988497A (en) * 1985-05-03 1991-01-29 Boehringer Mannheim Gmbh Process for the optical determination of lipase
EP1042500A1 (fr) * 1997-12-19 2000-10-11 NEN Life Science Products, Inc. Dosage enzymatique utilisant un substrat en phase solide
EP1042500A4 (fr) * 1997-12-19 2004-12-29 Nen Life Science Prod Inc Dosage enzymatique utilisant un substrat en phase solide

Also Published As

Publication number Publication date
IL32910A0 (en) 1969-11-30
BE738960A (fr) 1970-03-17
DE1943454A1 (de) 1971-03-25
JPS5542703B1 (fr) 1980-11-01
CH506792A (de) 1971-04-30
SE372631B (fr) 1974-12-23
FR2022180A1 (fr) 1970-07-31
IL32910A (en) 1972-11-28
DE1798285A1 (de) 1972-01-20
GB1247449A (en) 1971-09-22
NL6913769A (fr) 1970-03-24
DE1798285B2 (de) 1976-02-12

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