scholarly journals A Critical Evaluation of a New Fluorescence Immunoassay System for the Measurement of Serum Phenytoin Concentrations

1983 ◽  
Vol 20 (5) ◽  
pp. 274-279 ◽  
Author(s):  
S J Davis ◽  
V Marks
Keyword(s):  
Liquid Chromatography ◽  
Enzyme Immunoassay ◽  
Temperature Control ◽  
Calibration Curve ◽  
Incubation Time ◽  
Incubation Temperature ◽  
Critical Evaluation ◽  
Fluorescence Immunoassay ◽  
Significant Interference ◽  
Single Calibration

Results are presented which show that the Ames TDA™ phenytoin kit may be used with a shortened incubation time (5 minutes) and that, using a Fluorostat™ instrument, a single calibration curve can be stored and used effectively over a three-week period. The importance of temperature control when using a single calibration curve is emphasised. An unexplained finding was that higher results were obtained for phenytoin concentrations up to about 15 mg/1 with increasing incubation temperature. There was acceptable precision of measurement at all levels of phenytoin concentration, and there was no significant interference by haemoglobin, bilirubin, or lipids. The TDA results correlated well with those obtained using liquid chromatography ( y=0·39 + 0·98 x, r=0·98, where y=TDA and x=HPLC) and enzyme immunoassay ( y=0·08 + 0·93 x, r=0·96, where y=TDA and x=EIA).

Ability of Inactivated Yeast Powder To Adsorb Patulin from Apple Juice

2012 ◽  
Vol 75 (3) ◽  
pp. 585-590 ◽  
Author(s):  
CAIXIA GUO ◽  
TIANLI YUE ◽  
SHAIMAA HATAB ◽  
YAHONG YUAN
Keyword(s):  
Incubation Time ◽  
Apple Juice ◽  
Incubation Temperature ◽  
Absolute Ethyl Alcohol ◽  
Initial Concentration ◽  
Different Temperatures ◽  
Yeast Powder ◽  
Commercial Yeast ◽  
The Stability ◽  
Phosphate Buffered Saline

This study aimed to investigate the adsorption of patulin from apple juice, using two types of inactivated yeast powder: laboratory-prepared yeast powder (LYP) and commercial yeast powder (CYP). The effects of incubation time, pH, incubation temperature, adsorbent amount, and initial concentration of patulin and the stability of the yeast-mycotoxin complex were assessed. The results showed that the efficiencies of the two yeast types in adsorbing patulin were similar. The ability of the powders to remove patulin increased with longer incubation times, and patulin concentration was below detectable levels with LYP and CYP at approximately 36 and 30 h, respectively. The highest removal of patulin was achieved at pH 5.0 for both powder types, and there were no significant differences in patulin decrease at different temperatures (4, 29, and 37°C). Additionally, the adsorption percentage of patulin increased significantly with the increase of absorbent amount and decrease of initial concentration of patulin. Stability of the yeast-patulin complex was assessed, and patulin was more stable when washed in phosphate-buffered saline (pH 4.0) than in absolute ethyl alcohol. These results suggest that inactivated yeast powder has potential as a novel and promising adsorbent to bind patulin effectively.

scholarly journals Enzyme optimization to reduce the viscosity of pitanga (Eugenia uniflora L.) juice

2016 ◽  
Vol 19 (0) ◽  
Author(s):  
Ricardo Schmitz Ongaratto ◽  
Luiz Antonio Viotto
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Incubation Time ◽  
Regression Models ◽  
Incubation Temperature ◽  
Correlation Coefficients ◽  
Enzyme Concentration ◽  
Optimum Conditions ◽  
Activity Time ◽  
Independent Variables

Summary The aim of this work was to separately evaluate the effects of pectinase and cellulase on the viscosity of pitanga juice, and determine the optimum conditions for their use employing response surface methodology. The independent variables were pectinase concentration (0-2.0 mg.g–1) and cellulase concentration (0-1.0 mg.g–1), activity time (10-110 min) and incubation temperature (23.2-56.8 °C). The use of pectinase and cellulase reduced the viscosity by about 15% and 25%, respectively. The results showed that enzyme concentration was the most important factor followed by activity time, and for the application of cellulase the incubation temperature had a significant effect too. The regression models showed correlation coefficients (R2) near to 0.90. The pectinase application conditions that led to the lowest viscosity were: concentration of 1.7 mg.g–1, incubation temperature of 37.6 °C and incubation time of 80 minutes, while for cellulase the values were: concentration of 1.0 mg.g-1, temperature range of 25 °C to 35 °C and incubation time of 110 minutes.

Use of Iron Milk Medium for Enumeration of Clostridium perfringens

1982 ◽  
Vol 65 (5) ◽  
pp. 1129-1133 ◽  
Author(s):  
William D St John ◽  
Jack R Matches ◽  
Marleen M Wekell
Keyword(s):  
Clostridium Perfringens ◽  
Incubation Time ◽  
Incubation Temperature ◽  
Egg Yolk ◽  
Most Probable Number ◽  
Biochemical Tests ◽  
Probable Number ◽  
Large Numbers ◽  
Whole Milk ◽  
Short Incubation Time

Abstract A simple iron milk medium was used for isolation and enumeration of Clostridium perfringens from soil, sludge, and water samples. The whole milk contained only iron powder as a reducing agent; no other inhibitors were added. The iron milk most probable number (MPN) procedure was compared with 4 plating media: sulfite-polymyxin-sulfadiazine, Shahidi-Ferguson perfringens, tryptose-sulfite- cycloserine (both with and without egg yolk), and tryptone-sulfite-neomycin. The selectivity of the iron milk relies solely on the rapid growth of C. perfringens at 45°C and the stormy fermentation reaction within 18 h. Isolates were confirmed as C. perfringens by standard biochemical tests. The iron milk MPN procedure compared very well with the 4 plating media tested. Selectivity of incubation temperature, short incubation time, and ease of identification by the characteristic stormy fermentation make this method ideal for enumerating C. perfringens from large numbers of samples.

Assay of Phenobarbital: Adaptation of "EMIT" to the Centrifugal Analyzer

1977 ◽  
Vol 23 (4) ◽  
pp. 738-740 ◽  
Author(s):  
Paul R Finley ◽  
R Jane Williams ◽  
Donald F Lichti ◽  
James M Byers
Keyword(s):  
Liquid Chromatography ◽  
Enzyme Immunoassay ◽  
Gas Liquid Chromatography ◽  
Logit Transformation ◽  
Precision And Accuracy ◽  
Absorbance Data

Abstract We have adapted the centrifugal analyzer to the homo-geneous enzyme immunoassay ("EMIT"®) for phenobar-bital. The assay was modified to give greater range and sensitivity, and less reagent is needed. The transfer disc is prepared with totally automatic pipetting. Results are calculated with a micro-computer that provides a logit transformation of absorbance data. Precision and accuracy are excellent, and results correlate well with those by gas—liquid chromatography.

BRAIN NATRIURETIC PEPTIDE (BNP) SEBAGAI BIOMARKER GAGAL JANTUNG KONGESTIF

2020 ◽  
Vol 10 (3) ◽  
pp. 130-138
Author(s):  
Budi Sembiring ◽  
◽  
Jekson Siahaan
Keyword(s):  
Heart Failure ◽  
Brain Natriuretic Peptide ◽  
Enzyme Immunoassay ◽  
Natriuretic Peptide ◽  
Fluorescence Immunoassay ◽  
Renin Angiotensin ◽  
Heart Ventricles ◽  
Immuno Assay

Brain Natriuretic Peptide (BNP) is mainly secreted by the heart ventricles and acts as antagonist to Renin-Angiotensin-Aldosterone. BNP is secreted as pre-proBNP which is broken down into BNP and proBNP in circulation. The BNP examination is done by measuring the levels of BNP or N-Terminal-proBNP depending on the method and the manufacturer. Increased levels of BNP and NT-proBNP indicate heart failure so that BNP and NT-proBNP are considered markers of heart failure. This examination is also indicated to help establish the diagnosis, monitoring, and prognosis of heart failure. Natriuretic peptide examination can be done by several methods such as radioimmunoassay (RIA), Enzyme immunoassay (EIA), Fluorescence immunoassay (FIA), and Sandwich Electro Chemiluminescence Immuno Assay (Sandwich ECLIA).

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