Simple enzymatic determination of total cholesterol in gallstones.

1989 ◽  
Vol 35 (11) ◽  
pp. 2247-2249 ◽  
Author(s):  
J S Wei ◽  
H M Huang ◽  
W C Shyu ◽  
C S Wu
Keyword(s):  
Total Cholesterol ◽  
Dimethyl Sulfoxide ◽  
Organic Solvents ◽  
Cholesterol Oxidase ◽  
Enzymatic Activities ◽  
Simple Method ◽  
Spectroscopic Measurements ◽  
Assay Mixture ◽  
Enzymatic Determination

Abstract In this simple method for rapid enzymatic determination of total cholesterol in human gallstones, gallstone powder is dissolved in an 80/20 by vol mixture of N,N-dimethylformamide and dimethyl sulfoxide and reacted directly with the aqueous enzymatic reagent, without further treatment. The organic solvents do not interfere with enzymatic activities of cholesterol oxidase, esterase, and peroxidase in the assay mixture. The method is reproducible (CVs 3.7% to 6.6%), analytical recoveries ranged from 98.6% to 102%, and linearity is good. Furthermore, results correlated well with those obtained by infrared spectroscopic measurements.

Improved enzymatic determination of total cholesterol in tissues.

1983 ◽  
Vol 29 (1) ◽  
pp. 166-168 ◽  
Author(s):  
B H Cho
Keyword(s):  
Enzymatic Activity ◽  
Total Cholesterol ◽  
Aqueous Medium ◽  
Organic Solvents ◽  
Tissue Lipid ◽  
Improved Method ◽  
Enzymatic Determination

Abstract In this improved method for rapid enzymatic determination of total cholesterol, the lipid extracts from tissues are dissolved in an equal volume of peroxide-free dioxane/isopropanol (50/50 by vol) solution, and are reacted directly with the aqueous enzymatic reagent, without further treatment. The presence of organic solvents, such as dioxane and isopropanol, does not interfere with enzymatic activity. This simpler procedure eliminates the tedious solubilization of tissue lipid extracts into an aqueous medium. The method is reproducible, and results correlate well with those by a chemical (FeCl3/H2SO4) method.

scholarly journals A simple method for the determination of the cholesterol esterase activity.

2013 ◽  
Vol 60 (3) ◽  
Author(s):  
Agnieszka Ewa Stępień ◽  
Mykhailo Gonchar
Keyword(s):  
Human Serum ◽  
Esterase Activity ◽  
Cholesterol Oxidase ◽  
Cholesterol Esterase ◽  
Cholesterol Esters ◽  
Simple Method ◽  
Bacterial Enzyme ◽  
Low Costs ◽  
Hydrolysis Of

The proposed method determines the activity of cholesterol esterase (CEH) and takes advantage of its ability to catalyze the hydrolysis of cholesterol esters naturally present in human serum. The assay is based on Allain's method of spectrophotometric determination of cholesterol by means of cholesterol oxidase, peroxidase, but using 3,5-dichloro-dihydroxybenzenesulfonic acid (DHBS) as phenolic chromogen and human serum as a source of substrate for the CEH as a novelty. Furthermore, it is characterized by low costs and high precision. It can be employed to control the activity of CE preparations used for the preparation of enzymatic kits for the determination of cholesterol or for screening of potential bacterial enzyme producers.

Direct Fluorometric Determination of Total Cholesterol in Serum Using Derivatized Cholesterol Oxidase

2000 ◽  
Vol 54 (8) ◽  
pp. 1157-1162 ◽  
Author(s):  
Javier Galbán ◽  
José F. Sierra ◽  
José M. López Sebastian ◽  
Susana de Marcos ◽  
Juan R. Castillo
Keyword(s):  
Blood Serum ◽  
Total Cholesterol ◽  
Cholesterol Oxidase ◽  
Enzymatic Reaction ◽  
Direct Determination ◽  
Analytical Signal ◽  
Cholesterol Concentration ◽  
Serum Samples ◽  
Response Range

In this paper the use of cholesterol oxidase derivatized with a fluorescein derivative is proposed for the direct determination of total cholesterol in blood serum. The method is based on the changes in the fluorescence of the solution during the enzymatic reaction (λexe = 498 nm and λem 519 nm). A mathematical model which relates the analytical signal to the total cholesterol concentration was developed, and the model can also be used to obtain some of the thermodynamic constants of the process. The method has a linear response range up to 70 mg/L of cholesterol, a detection limit of 2.5 mg/L, and the precision was 1.0% (40 mg/L cholesterol, n = 10). The method was applied to total cholesterol determination in blood serum samples. The results were compared to those obtained by a commercial analyzer, and statistically similar results were obtained. The use of derivatized cholesterol oxidase makes it possible to simplify the methodology normally used in this type of determination (the indicator reaction is avoided and the number of reagents reduced), with the added advantage that the analytical signal is independent of the concentrations of O2 and cholesterol oxidase.

Enzymatic Determination of Total Cholesterol in Serum

1974 ◽  
Vol 20 (6) ◽  
pp. 724-725 ◽  
Author(s):  
P N Tarbutton ◽  
C R Gunter
Keyword(s):  
Total Cholesterol ◽  
Enzymatic Determination

Simple enzymatic determination of total cholesterol in gallstones compared with intrared spectrophotometry method

1998 ◽  
Vol 114 ◽  
pp. A1266
Author(s):  
M.S. Joo ◽  
D.H. Lee ◽  
W. Choi ◽  
P.S. Kim ◽  
Y.S. Kim
Keyword(s):  
Total Cholesterol ◽  
Enzymatic Determination

scholarly journals Determination of HDL-Cholesterol Using 2,4,6-Tribromo-3-Hydroxybenzoic Acid with a Commercial CHOD—PAP Reagent

1984 ◽  
Vol 21 (5) ◽  
pp. 430-433 ◽  
Author(s):  
Paul Trinder ◽  
David Webster
Keyword(s):  
High Performance ◽  
Cholesterol Oxidase ◽  
Hdl Cholesterol ◽  
High Sensitivity ◽  
Hydroxybenzoic Acid ◽  
Simple Method ◽  
Fourfold Increase

The Boehringer one-component high-performance cholesterol oxidase reagent has been modified by the inclusion of 2,4,6-tribromo-3-hydroxybenzoic acid (TBHBA) to give a fourfold increase in sensitivity to a molar absorbance of ≈ 29 000 with respect to cholesterol. The resulting reagent system is particularly suitable for the determination of plasma HDL-cholesterol for which a reagent of high sensitivity is required. A simple method of bromination avoiding the use of elemental bromine is used to prepare TBHBA. The modified reagent system has been found to have good within- and between-batch precision and has shown itself to be reliable and trouble-free.

Enzymatic Determination of Total Serum Cholesterol

1974 ◽  
Vol 20 (4) ◽  
pp. 470-475 ◽  
Author(s):  
Charles C Allain ◽  
Lucy S Poon ◽  
Cicely S G Chan ◽  
W Richmond ◽  
Paul C Fu
Keyword(s):  
Serum Cholesterol ◽  
Free Cholesterol ◽  
Cholesterol Oxidase ◽  
Total Serum ◽  
Total Serum Cholesterol ◽  
Enzymatic Method ◽  
Simultaneous Production ◽  
Enzymatic Determination ◽  
Production Of Hydrogen

Abstract An enzymatic method is described for determination of total serum cholesterol by use of a single aqueous reagent. The method requires no prior treatment of sample and the calibration curve is linear to 600 mg/dl. Cholesterol esters are hydrolyzed to free cholesterol by cholesterol ester hydrolase (EC 3.1.1.13). The free cholesterol produced is oxidized by cholesterol oxidase to cholest-4-en-3-one with the simultaneous production of hydrogen peroxide, which oxidatively couples with 4-aminoantipyrine and phenol in the presence of peroxidase to yield a chromogen with maximum absorption at 500 nm. The method is reproducible, and the results correlate well with those obtained by automated Liebermann—Burchard procedures (AA-2 and SMA 12/60) and the method of Abell et al. The present method affords better specificity than those previously reported and has excellent precision.

Reagent for the enzymatic determination of serum total cholesterol with improved lipolytic efficiency.

1983 ◽  
Vol 29 (6) ◽  
pp. 1075-1080 ◽  
Author(s):  
J Siedel ◽  
E O Hägele ◽  
J Ziegenhorn ◽  
A W Wahlefeld
Keyword(s):  
Total Cholesterol ◽  
Cholesterol Ester ◽  
High Performance ◽  
Serum Lipids ◽  
Serum Total Cholesterol ◽  
Enzymatic Determination ◽  
Layer Chromatography ◽  
Chloroform Methanol ◽  
Hydrolysis Of

Abstract We describe a sensitive method for quantifying the extent of cholesterol ester cleavage during enzymatic assay of total cholesterol in serum. Lipids are extracted from the assay mixture with chloroform/methanol (1/1 by vol), concentrated, then quantified by "high-performance" thin-layer chromatography. Although with conventional enzymatic reagents for determination of serum total cholesterol the hydrolysis of the cholesterol esters may be incomplete, a new enzymatic cholesterol reagent (Monotest Cholesterol, High Performance, Boehringer Mannheim) gives virtually complete cholesterol ester cleavage (i.e., greater than or equal to 99.5%). Use of this reagent with its improved lipolytic efficiency yields results for serum total cholesterol that are identical to those measured with a candidate reference procedure involving alkaline cholesterol ester saponification.

Sign in / Sign up

Export Citation Format

Share Document