Determination of Bovine Proteins using Agarose Gel Electrophoresis Comparing lipoproteins to a Wet Chemistry TechniqueAuthor(s): Dakshita Mehra, Priya Dhami, Chiranjeev Bisht
Serum lipoprotein quantification can tell you how well dairy cattle's hepatic and metabolic systems are working as well as how much lipid is being mobilized. Reagents designed for human lipoproteins are used in automated assays run on tabletop chemistry analyzers and with commercially available kits. The application of these assays for analyzing bovine lipoproteins may be complicated by the significant physical and chemical variations between those proteins and those found in humans and cattle. In order to semi-quantify the HighDensity Lipoprotein (HDL) and Low-Density Lipoprotein (LDL) fractions by optical densitometry, 56 Holstein cows' serum lipoproteins were prospectively examined in this study. The electrophoretic lipoprotein separation pattern was verified by ultracentrifugation. The results of the electrophoretic approach were compared to estimated LDL cholesterol as well as those from direct measurements of HDL cholesterol, total cholesterol, and Triglyceride (TG) concentrations on a Roche chemical analyzer. It was unable to compute the correlation between these approaches for LDL and it was bad for HDL (Passing-Bablok regression line: y = 30.31 + 0.853x). In 25 of the 56 samples, automated HDL readings were equal to or greater than the total cholesterol level. 18 samples had TG amounts above the reference range, and on average, 96% of the cholesterol in these samples was determined to be HDL by an automated approach and 78% by electrophoresis. Our findings call into question the precision of the Roche automated assay in quantifying bovine lipoprotein fractions given that it is physiologically impossible to have more cholesterol within the HDL fraction than in the total serum fraction and the increased proportion of TG found in LDL and very-low-density lipoprotein.