Abstract: The present invention provides a process for the determination of low density lipoproteins (LDL) in body fluids, wherein high density lipoprotein (HDL) antibodies are added to a sample to be investigated, insolubles formed are separated off and the LDL or one of its components is determined in the supernatant. The present invention also provides a reagent for the determination of the LDL fraction in body fluids, wherein it contains HDL antibodies.

Abstract: The present invention provides a process for the determination of low density lipoproteins (LDL) in body fluids, wherein high density lipoprotein (HDL) antibodies are added to a sample to be investigated, insolubles formed are separated off and the LDL or one of its components is determined in the supernatant.The present invention also provides a reagent for the determination of the LDL fraction in body fluids, wherein it contains HDL antibodies.

Abstract: The present invention provides a process for the specific determination of the serum fructosamine content in blood or samples derived from blood by reaction with an appropriate color reagent and measurement of the color change thereby brought about, wherein, before the color reaction, non-specific reducing-acting and/or turbidity-causing sample components are removed at approximately neutral pH value, subsequently the pH is adjusted to a value of from 10 to 12 and the color reagent is added thereto.The present invention also provides a reagent mixture for the specific determination of the serum fructosamine content in blood or samples derived from blood, wherein it comprises a reagent for the removal of non-specific reducing-acting and/or turbidity-causing sample components, a rebuffering reagent with a buffer which has a pH value in the range of from 10.5 to 12.5 and a color reagent for the detection of fructosamine.

Abstract: A process for the determination of substrate or enzyme activities by the use of a redox reaction as a measurement reaction is carried out in the presence of one or more additionally added tetrazolium salts to remove disturbing substances. The tetrazolium salts have the formula ##STR1## in which R.sup.1 is a hydrogen atom, a carboxyl group or an alkyl, phenyl, nitrophenyl, dinitrophenyl, carboxyl-substituted phenyl or trialkylammoniumphenyl radical, R.sup.2 is a phenyl, nitrophenyl, biphenylyl or naphthyl radical, R.sup.3 is a phenyl, carboxyl-substituted phenyl, carboxyl-substituted hydroxyphenyl or dimethylthiazolyl radical, and A.sup..crclbar. is a monovalent anion. The formazanes formed by reaction with reducing substances do not absorb light at all, or absorb light only to a negligible extent, at the measurement wavelength of the redox reaction.New compounds included within the structural formula are those in which R.sup.

Abstract: This invention teaches a process for reducing protein matrix effects in assays for serum fructosamine. Blood or blood derived samples are used, and one adds two reagents, one of which reduces interference caused by non-specific reducing substances, the other of which eliminates turbidity. Incubation follows, and then the pH of the sample is adjusted and color forming reagent is added. In one embodiment, the incubation time is only 1-15 minutes. In another embodiment, the first reagent contains peroxidase.

Abstract: Process for the specific determination of the serum fructosamine content in blood or in samples obtained from blood by reaction with an appropriate color reagent and measurement of the color change thereby brought about, in which before the color reaction sample components with a non-specific reducing action and/or causing turbidity are removed and subsequently the color reagent is added at a pH value of from 10 to 12. The sample components are removed by treatment at approximately neutral pH value with a reagent composition comprising at least one enzymatic oxidation agent, optionally together with peroxidase and/or catalase and/or lipase, as well as with at least one SH group-blocking substance. A kit for the specific determination of the serum fructosamine content in blood or samples obtained from blood, comprises said reagent composition, a rebuffering reagent with a buffer which has an alkaline pH value and a color reagent for the detection of fructosamine.

Abstract: .alpha.-Amylase is determined by the enzymatic splitting of an .alpha.-amylase substrate and measurement of a fission product, wherein there is used as a substrate a maltoheptaose compound of the formula ##STR1## wherein R is a glucoside, phenylglucoside, mononitrophenylglucoside, dinitrophenylglucoside, sorbitol or gluconic acid group. Reagents comprising such a substrate and a system for the determination of a fission product formed from the amylase substrate by .alpha.-amylase, are also provided. A process for the preparation of a maltoheptaose will Bacillus macerans amylase, free of p-nitrophenyl-alpha-glucoside splitting activity is disclosed.

Abstract: The present invention provides a process for the improved colorimetric determination of hydrogen peroxide as formed by a hydrogen peroxide-producing oxidase, by addition of a chromogenic system and measurement of the colored material formed, wherein superoxide dismutase (E.C. 1.15.1.1) is added to the reagent solution.The present invention also provides a reagent for the improved colorimetric determination of hydrogen peroxide, comprising a hydrogen peroxide-producing oxidase, a chromogenic system, a buffer and optionally adjuvant enzymes, wherein it also contains superoxide dismutase.

Abstract: A process for the determination of fructosamine in body fluids by the reaction of a sample solution with a color reagent, wherein the sample liquid is mixed with a buffer solution having a pH value of from 9 to 12, a color-forming reagent and uricase, as well as with at least one detergent, and the chronological change of the extinction is measured kinetically in a temperature range of from 20.degree. to 40.degree. C. at the earliest after 5 minutes.

Abstract: A process for the determination of substrate or enzyme activities by the use of a redox reaction as a measurement reaction is carried out in the presence of one or more additionally added tetrazolium salts to remove disturbing substances. The tetrazolium salts have the formula ##STR1## in which R.sup.1 is a hydrogen atom, a carboxyl group or an alkyl, phenyl, nitrophenyl, dinitrophenyl, carboxyl-substituted phenyl or trialkylammoniumphenyl radical, R.sup.2 is a phenyl, nitrophenyl, biphenylyl or naphthyl radical, R.sup.3 is a phenyl, carboxyl-substituted phenyl, carboxyl-substituted hydroxyphenyl or dimethylthiazolyl radical, and A.sup..crclbar. is a monovalent anion. The formazanes formed by reaction with reducing substances do not absorb light at all, or absorb light only to a negligible extent, at the measurement wavelength of the redox reaction. New compounds included within the formula are those in which R.sup.

Abstract: The present invention provides a process for the determination of total bilirubin in samples of body fluids. The method comprises the incubation of a sample of body fluid with both subtilisin which completely liberates bilirubin from its albumin and with bilirubin oxidase as a measurement of total bilirubin content in said body fluid sample.

Abstract: The present invention provides a process for the specific determination of the cholesterol of the HDL fraction in the presence of the LDL fraction of serum lipoproteins. Pancreatic cholesterol esterase is used to liberate cholesterol, and the liberated cholesterol then reacts with cholesterol oxidase and oxygen to form hydrogen peroxide. The kinetics of either of hydrogen peroxide formation or oxygen consumption is measured within 2 to 15 minutes after the start of the reaction between cholesterol and the oxidase. The temperature is maintained within a range of 20.degree. C., during a predetermined time interval. Specific concentrations of reactants are maintained in the reaction solution, i.e., from 0.05 to 30 U/ml pancreatic cholesterol esterase; from 0.1 to 50 U/ml cholesterol oxidase; from 1.0 to 20 mMole/liter of a tenside of the bile acid group, and 0.1 to 10 g/liter of a non-ionic detergent. The pH is kept within a range of 5 to 9.

Abstract: The present invention provides an aqueous cholesterol standard solution with a definite content of cholesterol, wherein it contains a detergent mixture of 10 to 90% of cholic acid and 90 to 10% of desoxycholic acid or of appropriate salts or derivatives of these acids.The present invention also provides a process for the preparation of this aqueous cholesterol standard solution, wherein a detergent mixture of cholic acid and desoxycholic acid or of appropriate salts and derivatives of these acids is dissolved in distilled water or in 0.9% aqueous sodium chloride solution, an appropriate preservation agent and/or a buffer effective in the pH range of from 7 to 9 optionally added thereto, and a definite, precisely defined amount of cholesterol is dissolved in the solution thus obtained, while stirring and warming to 40.degree. to 60.degree. C.

Abstract: The present invention provides a process for the specific determination of HDL cholesterol in serum or plasma by incubation with a cholesterol detection system, containing cholesterol oxidase and cholesterol esterase in a buffered aqueous medium, and measurement of a product of the cholesterol oxidase reaction or of the oxygen consumption, wherein a sample to be tested is incubated in the presence of a salt of a bile acid or of a bile acid derivative or of dioctylsulphosuccinate, a first measurement is then carried out, subsequently a non-ionic, polyethylene oxide group-containing detergent or a secondary alkane sulphonate is added, again incubated and a second measurement is carried out, the amount of HDL cholesterol being determined from the difference between the first and second measurement.

Abstract: The present invention provides 1-methylhydantoinase, which hydrolyses 1-methylhydantoin in the presence of a nucleoside triphosphate and of polyvalent metal ions.The present invention also provides a process for obtaining 1-methylhydantoinase and a reagent containing it.Furthermore, the present invention provides a process for the determination of creatinine by the conversion of the creatinine with creatinine deiminase (E.C. 3.5.4.21) into 1-methylhydantoin, hydrolysis of the latter with the 1-methylhydantoinase in the presence of nucleoside triphosphate and of polyvalent metal ions and determination(a) of the hydrolysis product formed from 1-methylhydantoin with N-carbamoylsarcosinamidohydrolase with formation of sarcosine and detection of the sarcosine with sarcosine oxidase or sarcosine dehydrogenase or(b) of the simultaneously formed nucleoside diphosphate.

Abstract: A method for determining low density lipoproteins (LDLs) in a body fluid sample, as well as a reagent suited for this use, are taught. The method involves precipitating high density lipoproteins (HDLs) from the sample, using an HDL specific antibody or reactive fragment, and then determining the presence and amount of LDL in the supernatant which results. The reagent contains the HDL specific antibodies, as well as polyanions and divalent cations.

Abstract: For the enzymatic determination of urea, one reacts the urea with glyoxylate in the presence of ureidoglycolate synthetase to give (S)-ureidoglycolate and oxidizes the latter with NAD(P).sup.+ and ureidoglycolate dehydrogenase to carbamoyloxamate and measures NAD(P)H formed either directly or via a color indicator system. A reagent suitable herefor contains glyoxylate, NAD(P).sup.+, (S)-ureidoglycolate synthetase, ureidoglycolate dehydrogenase and buffer substance.

Abstract: The present invention provides an agent for the removal of a turbidity in a biological fluid, wherein it contains(a) a polyethoxylated triglyceride with an HLB value of 4 to 14,(b) a secondary n-alkane sulphonate, as well as optionally(c) a futher non- or anionic tenside, in aqueous, optionally buffered solution.

Abstract: The present invention provides a process for the determination of glycerol in free or bound form by reaction with ATP in the presence of glycerol kinase (GK) and optionally of a hydrolase with the formation of glycerol-3-phosphate and ADP and determination of one of these reaction products with the help of at least one subsequent enzymatic reaction, wherein the determination is carried out kinetically and, for this purpose, the reaction with ATP is made rate-determining for the whole reaction and this is allowed to proceed according to the pseudo-first order in that there is added a sugar of the general formula: ##STR1## in which carbon atoms 2 and 3 have the D-threo configuration and R is a carbohydrate radical containing up to 3 carbon atoms and in which one hydroxyl group can also be replaced by a hydrogen atom.

Abstract: The present invention provides a process for the determination of the hemoglobin-haptoglobin complex in the presence of free hemoglobin by utilization of the different peroxidate properties of free and of bound hemoglobin, wherein, for the selective inhibition of the peroxidase activity of the free hemoglobin, a detergent is added and the residual peroxidate activity of the reaction mixture is measured.The present invention also provides a reagent for carrying out this process wherein, besides the substances required for the determination of the peroxidase activity, it contains a detergent for the inhibition of the peroxidase activity of free hemoglobin.Furthermore, the present invention provides a process for determining the haptoglobin content of a sample, as well as a process for determining glycosilated hemoglobin in a sample.