Evaluation of the Adaptation of the Glucose Oxidase/Peroxidase-3-Methyl-2-benzothiazolinone hydrazone-N, N-Dimethylaniline Procedure to the Technicon "SMA 12/60," and Comparison with Other Automated Methods for Glucose

1974 ◽  
Vol 20 (5) ◽  
pp. 595-602 ◽  
Author(s):  
R Neill Carey ◽  
Donald Feldbruegge ◽  
James O Westgard
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Standard Deviation ◽  
Glucose Oxidase ◽  
Sulfonic Acid ◽  
Reference Method ◽  
Acid Therapy ◽  
Control Product ◽  
The Mean ◽  
Automated Methods

Abstract We have evaluated the Technicon SMA 12/60 modification of a glucose oxidase/peroxidase-3-methyl-2-benzothiazolinone hydrazone-N, N-dimethylaniline method, and find it acceptable. Added bilirubin, creatinine, dextrans, and uric acid did not interfere. We compared values for patients’ sera by this method to those by the glucose oxidase/peroxidase-2,2'-azinodiethylbenzothiazoline-6-sulfonic acid, neocuproine, o-toluidine, ferricyanide, and hexokinase methods. For comparisons to the hexokinase method (which we used as a reference method), n = 371, slope = 1.00, y-intercept = 1.57 mg/dl, and bias = 2.05 mg/dl. For the method being evaluated, the run-to-run average monthly standard deviation was 2.9 mg/dl for a control product for which the mean was 85 mg of glucose per deciliter, and 4.3 mg/dl for a product for which the mean was 240 mg/dl. All six methods were compared for effects of uremic sera, icteric sera, and sera from patients receiving ascorbic acid therapy or hypoglycemic drugs.

Evaluation of a Glucose Oxidase-Peroxidase Method Adapted to the Single-Channel AutoAnalyzer and SMA 12/60

1973 ◽  
Vol 19 (2) ◽  
pp. 253-257 ◽  
Author(s):  
Stanley J Miskiewicz ◽  
Bill B Arnett ◽  
Gerald E Simon
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Glucose Oxidase ◽  
Ammonium Salt ◽  
Glucose Concentration ◽  
Sulfonic Acid ◽  
Single Channel ◽  
Serum Glucose ◽  
Elevated Bilirubin ◽  
Uremic Patients

Abstract The glucose oxidase—peroxidase method for determining serum glucose, with the ammonium salt of 2,2'-azine-di - (3 - ethyl - benzothiazoline-(6)-sulfonic acid) as the chromogen, was adapted to use with the single-channel AutoAnalyzer and the SMA 12/60 (Technicon Corp.). The extended linearity (up to 500 mg/100 ml on both systems) eliminated the need for numerous dilutions in the 300 to 500 mg/100 ml range as required by other methods of analysis. Recovery of added glucose was excellent. Supranormal concentrations of uric acid and ascorbic acid interfered with recovery, but the effects of elevated bilirubin, creatinine, and urea, and of gross hemolysis were negligible. Sera of 337 patients (glucose concentrations: 50 to 454 mg/100 ml) were analyzed by this method on both instruments and by an automated o-toluidine method. By the latter procedure, the glucose concentration averaged 10 mg/100 ml higher. Sera from uremic patients, measured by the o-toluidine method, had glucose values up to 28.0 mg/100 ml higher than the values obtained by the glucose oxidase method. The glucose oxidase method of measuring serum glucose is a more accurate and precise index of "true glucose" than either the o-toluidine or the neocuproine methods.

Evaluation of the co-immobilized hexokinase/glucose-6-phosphate dehydrogenase method for glucose, as adapted to the Technicon SMAC.

1978 ◽  
Vol 24 (7) ◽  
pp. 1186-1190 ◽  
Author(s):  
C C Garber ◽  
D Feldbruegge ◽  
R C Miller ◽  
R N Carey
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Glucose Oxidase ◽  
Total Error ◽  
Reference Method ◽  
Systematic Errors ◽  
Upper Limits ◽  
Rate Method ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Glucose Analysis

Abstract We assessed the analytical performance of the co-immobilized hexokinase (EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) method for D-glucose analysis on the Technicon SMAC. The enzyme-containing coils were usable for one month, or 12 000 tests. Bilirubin, hemoglobin, lipemia, creatinine, uric acid, citric acid, and ascorbic acid did not interfere. Results with this method were compared to those by the National Glucose Reference Method. The upper limits of the total error estimate (a combination of random and systematic errors) were 76, 74, and 125 mg/liter at concentrations of 500, 1200, and 3000 mg/liter, respectively. The error estimates were less than allowable errors based on medical usefulness; thus the method was judged to perform acceptably with respect to the Reference Method. We also present performance data for the routine SMAC glucose oxidase (EC 1.1.3.4)/Peroxidase (EC 1.11.1.7) 3-methyl-2-benzothianolinone hydrazone-N,N-dimethylaniline method, the direct hexokinase method with the Du Pont aca, and the glucose oxidase oxygen-rate method with the Beckman Glucose Analyzer.

Glucose Oxidase Method for Continuous Automated Blood Glucose Determination

1969 ◽  
Vol 15 (8) ◽  
pp. 680-698 ◽  
Author(s):  
John W Rosevear ◽  
Kenneth J Pfaff ◽  
Frederick J Service ◽  
George D Molnar ◽  
Eugene Ackerman
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Blood Glucose ◽  
Glucose Oxidase ◽  
Normal Subjects ◽  
Significant Inhibition ◽  
Total Response ◽  
Glucose Determination ◽  
Blood Glucose Determination ◽  
Sampling Catheter

Abstract A glucose oxidase-peroxidase method for continuous automated monitoring of blood glucose has been developed. The response is linear over the range 0-800 mg/100 ml. Sensitivity can be maintained for 24 hr or longer and can be restored by rinsing the analytic system with sulfuric acid to permit studies of longer than 48 hr in duration. A precision of ± 1% can be maintained between rinses for samples containing 100-600 mg of glucose per 100 ml. This method is satisfactorily specific for glucose: The response with other sugars is less than 1% of the response obtained with the same concentration of glucose. Ascorbic acid causes no significant inhibition of the response to glucose. The inhibition by uric acid has been reduced fifty-fold compared to that in other methods. Transit through the sampling catheter and analytic system requires 15 min. Timed from the first detectable response to a change in concentration, 25% of total response is achieved in 30 sec and 90% in 80 sec. Fifty percent of an oscillation with a half-period of 45 sec can be detected; no oscillations this short were observed in records of human blood glucose. Applicability and feasibility of this method have been demonstrated in over 2000 hr of repeated blood glucose recordings in 12 diabetic and 6 normal subjects.

Four methods for determining uric acid compared with a candidate reference method.

1982 ◽  
Vol 28 (10) ◽  
pp. 2098-2100 ◽  
Author(s):  
R J Elin ◽  
E Johnson ◽  
R Chesler
Keyword(s):  
Uric Acid ◽  
Regression Analysis ◽  
Linear Regression ◽  
Phosphotungstic Acid ◽  
Linear Regression Analysis ◽  
Reference Method ◽  
Mean Difference ◽  
Acid Method ◽  
The Mean ◽  
Smac Method

Abstract Uric acid as measured in serum by three different uricase (EC 1.7.3.3) methods (aca, Ektachem, and SMAC) and by the SMAC method with phosphotungstic acid was compared with a candidate Reference Method for uric acid. Serum specimens from 83 patients (uric acid concentrations, 19 to 141 mg/L) were analyzed by all five methods. Results were compared by using linear regression analysis, and the mean difference between results by the candidate Reference Method and the four other methods was calculated. Compared with the candidate Reference Method, the aca method gave the smallest deviation from zero for the intercept and the smallest mean difference, and the SMAC phosphotungstic acid method showed a slope closest to unity. The SMAC uricase method had the largest intercept and greatest deviation of the slope from unity.

t-PA PROTEIN DETERMINATION: IMPROVED ACCURACY THROUGH COMPOSITION CONSIOUS AMINO ACID ANALYSIS (CCAAA)

1987 ◽  
Author(s):  
A Brändström ◽  
M Rånby
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Standard Deviation ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Amino Acid Analysis ◽  
Reference Method ◽  
Protein Determination ◽  
Molar Quantity ◽  
The Mean

Protein determination by composition consious amino acid analysis (CCAAA) is generally applicable to polypeptides with known amino acid composition.Traditionally, in protein determination by AAA the mass of protein substance in a preparation is quantitated by simple summation of the mass of all amino acid residues found, although some amino acids e.g. Trp, Ser, Thr, Cys are unsatisfactorily determined. In this study we have explored the, possibility of improving protein determination by AAA in cases where the amino acid composition of the preparation is precisely known from sequence data. In CCAAA protein determination the molar amounts of amino acids that are known to be quantitatively recovered are divided by the number of residues known to be present in the polypeptide. The mean of these values is identified as the molar quantity of polypeptide in the sample. In addition, the standard deviation of the mean serves as identification and homogeneity control. In this study the accuracy of the method was checked gravimetrically.CCAAA was applied on t-PA prepared from cultured Bowes melanoma cells by immunopurification on PAMl-Sepharose 6BFF and subsequent gelfiltration in 1 mol/L NH4HCO3 on Sephacryl SA-200. About 2 pg of lyophilized protein was hydrolysed in 6 mol/L HC1 under vacuum for 24 hours at 110°C and amino acid analysed. Amino acids selected for calculation of the molar quantity were (number of residues within parentheses) Asp+Asn(50), Glu+Gln(52), Pro(29), Ala(32.5), Val(25), Leu(39), His(16), Lys(21) and Arg(35.5). To obtain the gravimetric quantity the molar quantity was multiplied with the theoretical molecular weight as calculated from the sequence and with the carbohydrate content taken into account.For t-PA the standard deviation of the mean molar quantity typically was less than 5%. The result from CCAAA was about 10% higher than that obtained from conventional AAA. The result from CCAAA was within 10% of that found gravimetrically. The absorbtivity of t-PA was estimated to 1.75 (g/L)-1cm-1.In summary, composition consious amino acid analysis (CCAAA) is recommended as reference method for protein determination of well defined protein preparations where the amino acid composition is known.

scholarly journals Simultaneous voltammetric detection of dopamine, ascorbic acid and uric acid using a poly(2-(N-morpholine)ethane sulfonic acid)/RGO modified electrode

RSC Advances ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 5280-5285 ◽  
Author(s):  
Keying Zhang ◽  
Na Zhang ◽  
Li Zhang ◽  
Hongyan Wang ◽  
Hongwei Shi ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Electrochemical Sensor ◽  
Modified Electrode ◽  
Sulfonic Acid ◽  
Voltammetric Detection

A sensitive electrochemical sensor for simultaneously detecting dopamine, ascorbic acid and uric acid.

scholarly journals Determining the Efficacy of Liquid Sporicides Against Spores of Bacillus subtilis on a Hard Nonporous Surface Using the Quantitative Three Step Method: Collaborative Study

2008 ◽  
Vol 91 (4) ◽  
pp. 833-852 ◽  
Author(s):  
Stephen F Tomasino ◽  
Rebecca M Pines ◽  
Michele P Cottrill ◽  
Martin A Hamilton ◽  
K Alvey ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Standard Deviation ◽  
Quantitative Methods ◽  
Collaborative Study ◽  
Reference Method ◽  
Step Method ◽  
Components Of Variance ◽  
Test Chemical ◽  
Validation Parameters ◽  
The Mean

Abstract A collaborative study was conducted to validate the quantitative Three Step Method (TSM), a method designed to measure the performance of liquid sporicides on a hard nonporous surface. Ten laboratories agreed to participate in the collaborative study; data from 8 of 10 participating laboratories were used in the final statistical analysis. The TSM uses 5 5 1 mm glass coupons (carriers) upon which spores have been inoculated and which are introduced into liquid sporicidal agent contained in a microcentrifuge tube. Following exposure to a test chemical and a neutralization agent, spores are removed from carriers in 3 fractions: passive removal (Fraction A), sonication (Fraction B), and gentle agitation (Fraction C). Liquid from each fraction is serially diluted and plated on a recovery medium for spore enumeration. Control counts are compared to the treated counts, and the level of efficacy is determined by calculating the log10 reduction (LR) of spores. The main statistical goals were to evaluate the repeatability and reproducibility of the LR values, to estimate the components of variance for LR, and to assess method responsiveness. AOAC Method 966.04Method II was used as a reference method. The scope of the validation was limited to testing liquid formulations against spores of Bacillus subtilis, a surrogate for virulent strains of B. anthracis, on a hard nonporous surface (glass). The test chemicals used in the study were sodium hypochlorite, a combination of peracetic acid and hydrogen peroxide, and glutaraldehyde. Each test chemical was evaluated at 3 levels of presumed efficacy: high, medium, and low. Three replications were required. The TSM was validated as it successfully met the statistical parameters for quantitative test methods. Satisfactory validation parameters, such as the repeatability standard deviation (Sr) and reproducibility standard deviation (SR), were obtained for control carrier counts and LR values. Both the TSM and the reference method were responsive to the efficacy levels of the test chemicals. For the 72 total TSM tests conducted, the mean ( standard error of the mean) log density of spores per control carrier was 6.86 ( 0.08); the Sr and SR were low at 0.15 and 0.27, respectively. Across the range of test chemicals, the Sr and SR estimates associated with LR were also acceptably low. The Sr rangedfrom 0.17 to 0.72 and the SR ranged from 0.34 to 1.43. Overall, the Sr and SR estimates associated with the efficacy data were within the ranges published for other quantitative methods and meet the performance characteristics necessary for validation.

Modified Glucose Oxidase Method for Determination of Glucose in Whole Blood

1973 ◽  
Vol 19 (3) ◽  
pp. 308-311 ◽  
Author(s):  
Samuel Meites ◽  
Karen Saniel-Banrey
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Glucose Oxidase ◽  
Whole Blood ◽  
Enzyme Concentration ◽  
Capillary Blood ◽  
Protein Precipitation ◽  
Analytical Time

Abstract We have modified an ultramicro method for determining glucose with glucose oxidase—peroxidase—odianisidine. Capillary blood is diluted in isotonic NaF (17.6-17.8 g/ liter), the cells are removed, and glucose is determined after a 20-min incubation with enzyme-containing reagent. Increasing the enzyme concentration fourfold nullifies interference from ascorbic acid and hemolysis, while greatly decreasing interference from bilirubinemia. If necessary, bilirubin is removed completely by coprecipitation with protein. Interference from uric acid is minimized by incorporating it into the standards. Several other suspected interferences proved inconsequential. Isotonic NaF does not inhibit the enzymes used, and preserves glucose in blood for at least 2 h. Avoiding protein precipitation and shortening the incubating time significantly lessens analytical time without affecting precision.

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