Quantification of Apolipoprotein A-1 in Cow Serum by Single Radial Immunodiffusion

Abstract
A single radial immunodiffusion assay was developed to determine the concentration of the major apolipoproetin A-I in bovine serum. Assay was performed using agarose gel plates with monospecific rabbit antiserum. Standards made with bovine high density lipoproteins or serum 10 times diluted were applied in 3-.mu.l amounts to each well in the gel. The assay working range was 2 to 22 mg of apolipoprotein A-I. The intraassay and interassay CV were 3.7 and 4.9%, respectively. Using protein A-I. The intrassay CY were 3.7 and 4.9%, respectively. Using radial immunodiffusion assay, 23 serum samples from cows at various stages of lactation were analyzed. Apolipoprotein A-I was significantly increased in midlactation compared with concentrations in early lactation or dry period.