Kinetic enzymic method for automated determination of total cholesterol in serum.

Abstract

We describe a rapid, kinetic, fixed-time method for determining serum total cholesterol by use of cholesterol esterase, cholesterol oxidase, and the indicator reaction with peroxidase, 4-aminophenazone, and phenol. On addition of the competitive inhibitor 3,4-dichlorophenol the Michaelis constant of cholesterol oxidase is apparently increased, which extends the linear relation between absorbance change and cholesterol concentration to 20.7 to 25.9 mmol/L, depending on the analyzer being used. For calibration, a single standard is used. Total analysis time is in the range of 80 to 210 s. Incubation temperature is 25 degrees C or 37 degrees C. The single-reagent procedure has been adapted to three different centrifugal analyzers and to the Eppendorf ACP 5040 analyzer. It yields precise and accurate results and is insensitive to potential interferences.

Porcine Pancreas: A Superior Source of Cholesterol Esterase for Total Serum Cholesterol Assay by the Enzymatic Kinetic Method

“…The maximal cholesterol linearity was observed for reagents containing P. fluorescens enzyme of 400 U/l, which is similar to report of Deeg and Ziegenhorn (6). However, we selected the enzyme activity at 200 U/l, which gave the suitable linearity up to 16.3 mmol/l.…”

Effects of Chinese herbal mixture on performance, egg quality and blood biochemical parameters of laying hens

“…Albumin in serum was determined by colorimetric test using the bromcresol green dyebinding procedure (Beng and Lim, 1973). The TC and HDL-C were measured by enzymatic photometric method (CHOD-PAP method; Deeg and Ziegenhorn, 1983) as well as TG by the colorimetric enzyme method of Fossati and Prencipe (1982). Additionally, ALT and AST activities were analysed using the optimized UV test according to IFCC modified method without pyridoxal phosphate (Siekmann et al, 2002).…”

The Nature of the Ingested Protein Has No Effect on Lean Body Mass During Energy Restriction in Overweight Rats

“…Plasma insulin levels were quantified using a commercial RIA kit (LINCO Research, Labodia, France). All other plasma measurements were performed using commercial kit from Horiba ABX (Montpellier, France): glucose using an enzyme-linked procedure based on a glucose oxidase/peroxidase method, triglycerides, enzymatically, total cholesterol, and high-density lipoprotein cholesterol, colorimetrically, with a cholesterol oxidase method "CHOD-PAP" (16). Plasma amino acids were purified by ion exchange chromatography after protein precipitation as previously described (13).…”