Quantitative Determination of Serum Triglycerides by the Use of Enzymes

1973 ◽  
Vol 19 (5) ◽  
pp. 476-482 ◽  
Author(s):  
Giovanni Bucolo ◽  
Harold David

Abstract We describe a novel method for determining serum triglycerides, in which an enzymatic hydrolysis replaces the more commonly used saponification procedure. Under the conditions of the assay, the enzymatic hydrolysis can be completed in less than 10 min by the combined action of a microbial lipase and a protease. We have been able to demonstrate complete hydrolysis of triglycerides by thin-layer chromatography of the reaction products, by recovery of glycerol from sera of known triglycerides content, and by comparison of triglyceride assays on a number of sera assayed by our method vs. the AutoAnalyzer procedure. The hydrolysis is directly coupled to the enzymatic determination of glycerol, and is followed through absorbance changes at 340 nm. The assay is simple, rapid, and requires only 50 µl or less of sample. Because the enzymes used do not release glycerol from other compounds in serum, the hydrolysis can be considered specific for triglycerides.

1983 ◽  
Vol 29 (6) ◽  
pp. 1075-1080 ◽  
Author(s):  
J Siedel ◽  
E O Hägele ◽  
J Ziegenhorn ◽  
A W Wahlefeld

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.


1983 ◽  
Vol 29 (8) ◽  
pp. 1513-1517 ◽  
Author(s):  
M W McGowan ◽  
J D Artiss ◽  
B Zak

Abstract A procedure for the enzymatic determination of lecithin and sphingomyelin in aqueous solution is described. The phospholipids are first dissolved in chloroform:methanol (2:1 by vol), the solvent is evaporated, and the residue is redissolved in an aqueous zwitterionic detergent solution. The enzymatic reaction sequences of both assays involve hydrolysis of the phospholipids to produce choline, which is then oxidized to betaine, thus generating hydrogen peroxide. The hydrogen peroxide is subsequently utilized in the enzymatic coupling of 4-aminoantipyrine and sodium 2-hydroxy-3,5-dichlorobenzenesulfonate, an intensely red color being formed. The presence of a non-reacting phospholipid enhances the hydrolysis of the reacting phospholipid. Thus we added lecithin to the sphingomyelin standards and sphingomyelin to the lecithin standards. This precise procedure may be applicable to determination of lecithin and sphingomyelin in amniotic fluid.


Soil Research ◽  
2004 ◽  
Vol 42 (7) ◽  
pp. 709 ◽  
Author(s):  
David F. Lambert ◽  
John E. Sherwood ◽  
Paul S. Francis

Although the dominant methods for the determination of urea in clinical applications incorporate selective enzymatic hydrolysis of urea, the determination of urea in soil extracts is complicated by the presence of urease inhibitors. The spectrophotometric determination of urea with an acidic solution diacetyl monoxime and semicarbazide is a viable option but traditional manual procedures are time-consuming. New variations on these procedures, based on microplates or flow-injection analysis methodologies, allow a far greater number of samples to be analysed with high precision and sensitivity.


2005 ◽  
Vol 22 (1) ◽  
pp. 19-29 ◽  
Author(s):  
F. C. Corazza ◽  
L. P. V. Calsavara ◽  
F. F. Moraes ◽  
G. M. Zanin ◽  
I. Neitzel

2011 ◽  
Vol 3 (3) ◽  
pp. 738 ◽  
Author(s):  
Michael Stiboller ◽  
Markus Damm ◽  
Allycia M. Barbera ◽  
Doris Kuehnelt ◽  
Kevin A. Francesconi ◽  
...  

2011 ◽  
Vol 102 (20) ◽  
pp. 9646-9652 ◽  
Author(s):  
Erinc Bahcegul ◽  
Emre Tatli ◽  
Nazife Isik Haykir ◽  
Serpil Apaydin ◽  
Ufuk Bakir

2016 ◽  
Vol 22 (3) ◽  
pp. 421-433 ◽  
Author(s):  
K. K. Asha ◽  
K. R. Remya Kumari ◽  
K. Ashok Kumar ◽  
Niladri S. Chatterjee ◽  
R. Anandan ◽  
...  

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