Enzyme Assay Methods to Validate DIGE Proteomics Data

2017 ◽  
pp. 279-286
Author(s):  
Andrew Dowd
Keyword(s):  
Enzyme Assay ◽  
Proteomics Data ◽  
Assay Methods

An ultrastructural and cytochemical study of microbodies in the genus Nitella (Characeae)

1973 ◽  
Vol 51 (11) ◽  
pp. 2025-2032 ◽  
Author(s):  
B. A. Silverberg ◽  
T. Sawa
Keyword(s):  
Enzyme Assay ◽  
The Body ◽  
Cytochemical Localization ◽  
Cytochemical Study ◽  
Spherical Inclusions ◽  
Complete Digestion ◽  
Assay Methods ◽  
Granular Matrix ◽  
Available Information

Electron microscopy of the cells of the characean alga Nitella flexilis revealed the presence of numerous spherical inclusions which morphologically resemble plant microbodies. The structures have a dense granular matrix and are bounded by a single membrane. Many of the microbodies contain very electron-dense nucleoids that were shown to be alpha-amylase sensitive. In cells of the young apex, microbodies are the most abundant cellular organelle and are intimately associated with dilated cisternae of the endoplasmic reticulum and Golgi complexes, and with large osmiophilic lipid bodies. Although the microbody population appears reduced in mature branchlet cells and internode cells of the main axis, they exhibit a characteristic and frequent association with the chloroplasts. Turnover of microbodies involves some autolytic degradation of the body matrix until complete digestion presumably occurs. Developmental changes of microbodies were monitored with the cytochemical localization of lysosomal aryl sulfatase and acid phosphatase activities. The current study is of interest since catalase, an enzyme marker of microbodies in a variety of tissues, could not be detected using both cytochemical and enzyme assay methods. The functional role of microbodies in Nitella cells is explored in relation to presently available information.

Evaluation of the Beckman "System TR Enzyme Analyzer"

1975 ◽  
Vol 21 (8) ◽  
pp. 1107-1112 ◽  
Author(s):  
Richard Passey ◽  
Ronald L Gillum ◽  
Mary Louise Giles ◽  
John B Fuller
Keyword(s):  
Temperature Control ◽  
Enzyme Assay ◽  
Product Evaluation ◽  
Analysis Time ◽  
Strip Chart Recorder ◽  
Strip Chart ◽  
Accuracy And Precision ◽  
Chart Recorder ◽  
Assay Methods ◽  
Carry Over

Abstract We evaluated 16 claims made by Beckman Instruments, Inc. for its Enzyme Analyzer (System TR), under a rigid written protocol for the Product Evaluation Subcommittee of the Standards Committee of the College of American Pathologists. We found the following to be within the company's specifications: (a) accuracy and precision of the temperature control; (b) accuracy and precision of the sample and reagent pipets; (c) instrument precision, both within-run and between-day; (d) carry-over from a sample with activity > 1000 U/liter; (e) instrument-to-instrument variation; (f) analytical linearity; (g) analysis time; (h) correlation of the instrumentprinted answer with the activity calculated manually from a strip-chart recorder; (i) precision of the instrument's built-in electronic "standard"; (j) effectiveness of the over-range indicators; and (k) correlation between results of these enzyme assay methods and those for kinetic methods used in our laboratory. The instrument performed well.

Evaluation of Direct and Indirect Coupled Enzyme Assay Systems for Measurement of Creatine Kinase Activity

1973 ◽  
Vol 19 (9) ◽  
pp. 994-997 ◽  
Author(s):  
E C Dinovo ◽  
D S Miyada ◽  
R M Nakamura
Keyword(s):  
Creatine Kinase ◽  
Enzyme Assay ◽  
Kinase Activity ◽  
Direct Method ◽  
Creatine Kinase Activity ◽  
Linear Range ◽  
Indirect Methods ◽  
Direct Assay ◽  
Assay Methods ◽  
Glucose 6 Phosphate Dehydrogenase

Abstract Direct assay of creatine kinase by the method of Siegel and Cohen with the Technicon "SMA 12/60" is compared with two indirect coupled-enzyme assay methods. The direct method was linear to greater than 2000 U/liter, whereas the indirect methods were linear to 250 and 1500 U/liter, with use of serial dilutions of a creatine kinase preparation. Increasing the activity of the auxiliary enzymes, hexokinase and glucose-6-phosphate dehydrogenase, in one of the coupled enzyme assay methods increased its linear range from 250 to 700 U/liter. The observed findings are explained on the basis of the fundamental differences between direct and indirect coupled-enzyme assay systems and, within the latter system, the effect of the activities of auxiliary enzymes.

Confirmation of Flixweed (Descurainia sophia) Resistance to Tribenuron-Methyl Using Three Different Assay Methods

Weed Science ◽  
2010 ◽  
Vol 58 (1) ◽  
pp. 56-60 ◽  
Author(s):  
Xian Xu ◽  
Gui Qi Wang ◽  
Si Long Chen ◽  
Cui Qin Fan ◽  
Bing Hua Li
Keyword(s):  
Enzyme Assay ◽  
Close Association ◽  
Resistance Mechanism ◽  
Petri Dish ◽  
Acetolactate Synthase ◽  
Resistance Level ◽  
Whole Plant ◽  
Plant Bioassay ◽  
Assay Methods ◽  
Tribenuron Methyl

Research was conducted to establish a method to investigate the resistance level of flixweed to tribenuron-methyl and the evolved biochemical resistance mechanism. Four resistant biotypes were collected from wheat fields in Mazhuangcun, Jiacun, Dishangcun, and Bafangcun in the Hebei province of China where tribenuron-methyl had been continuously used for more than 10 yr. Two susceptible biotypes were collected from wheat fields where tribenuron-methyl was never applied. Different biotypes were assessed by petri-dish bioassay, whole-plant bioassay, and acetolactate synthase (ALS) assay. Comparisons of data indicated a similarity between methods and that experiments demonstrated that petri-dish bioassay was a feasible method to identify flixweed resistant to tribenuron-methyl. Data indicated differences among the flixweed biotypes when assessed by the petri-dish bioassay, whole-plant bioassay, or ALS enzyme assay, and a close association was obtained for the three bioassay methods. ALS resistance varied by biotypes with Mazhuangcun > Jiacun > Dishangcun > Bafangcun. Target-site enzyme assay data indicated that the resistant biotype's enhanced ALS activity was the biochemical mechanism that induced flixweed's evolved resistance to tribenuron-methyl. The concentrations of tribenuron-methyl causing 50% inhibition of ALS activity of the four resistant biotypes were 1,359, 513, 184, and 164 nM; in the susceptible biotypes these concentrations were 64 and 65 nM. Resistance indexes were 21, 8, 3, and 3 for Mazhuangcun, Jiacun, Dishangcun, and Bafangcun biotypes, respectively.

Enzyme assay to study the influence of citalopram on the concentration of psychotropic comedication

2011 ◽  
Vol 44 (06) ◽  
Author(s):  
R Brandl ◽  
R Köber ◽  
T Jahner ◽  
A Dörfelt ◽  
E Haen
Keyword(s):  
Enzyme Assay

Lack of Agreement of Chromogenic and Glotting Assays for Factor X and Protein C in Warfarinised Plasma

1991 ◽  
Vol 65 (04) ◽  
pp. 360-363 ◽  
Author(s):  
P Han ◽  
K P Fung ◽  
U Rahdakrishnan
Keyword(s):  
Serine Proteases ◽  
Protein C ◽  
Warfarin Therapy ◽  
Intraclass Correlation ◽  
Chromogenic Substrate ◽  
Factor X ◽  
Laboratory Automation ◽  
Quantitative Results ◽  
Assay Methods

SummaryCoagulation serine proteases can be measured with either a chromogenic substrate assay or a clotting assay using deficient plasmas. It is a concern whether both assays give similar quantitative results, in particular in plasma obtained fiom patients on long term warfarin therapy. If these two assay methods were interchangeable, then the chromogenic substrate assay has the advantages of precision as well as laboratory automation. We used the intraclass correlation coefficient (r1) to assess the agreement between the two methods in measuring factor X and protein C levels in warfarinised plasma. The results indicate that the extent and pattern of agreement of the two methods for the measurement of the two variables in warfarinised plasma are poor, despite high Pearson product moment coefficients of correlation.

Assay Methods and Standard Preparations for Plasmin, Plasminogen and Urokinase in Purified Systems, 1967-1968

1969 ◽  
Vol 21 (02) ◽  
pp. 259-272 ◽  
Author(s):  
A. J Johnson ◽  
D. L Kline ◽  
Norma Alkjaersig
Keyword(s):  
Heart Institute ◽  
Thrombolytic Agents ◽  
National Heart ◽  
Assay Methods

SummaryTo facilitate communication between investigators, the Committee on Thrombolytic Agents of the National Heart Institute suggests standardized reagents and assay methods for the measurement of standard preparations of plasmin, plasminogen, and urokinase with use of casein, fibrin and synthetic esters as substrates.

A Collaborative Study Designed to Establish the 4th International Standard for Heparin

1984 ◽  
Vol 52 (02) ◽  
pp. 148-153 ◽  
Author(s):  
D P Thomas ◽  
A D Curtis ◽  
T W Barrowcliffe
Keyword(s):  
Collaborative Study ◽  
International Standard ◽  
Thrombin Inhibition ◽  
Freeze Dried ◽  
Assay Methods ◽  
The Mean ◽  
International Collaborative ◽  
International Collaborative Study

SummaryAn international collaborative study, in which 22 laboratories participated, was carried out to establish a replacement for the International Standard for Heparin. A total of 248 assays were analyzed, including APTT, thrombin inhibition and anti-Xa assays, as well as pharmacopoeial assays. Overall, there was less than 5% difference in the mean potency estimates of the candidate preparations, by all assay methods. The freeze-dried preparation 82/502 demonstrated the closest parallelism by bioassay to the existing standard and was established by WHO as the 4th International Standard for Heparin, with an assigned unitage of 1780 i.u. per ampoule.

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