Technical note: Comparison of radial immunodiffusion and ELISA for quantification of bovine immunoglobulin G in colostrum and plasma

Abstract

Historically, radial immunodiffusion (RID) has been the only method that directly measures IgG; however, recent studies have reported IgG concentrations in colostrum, milk, and plasma as measured using an ELISA. To our knowledge no comparison between RID and ELISA methods has been made for bovine colostrum or plasma. The objective of this study was to compare IgG concentrations measured by both methods in samples of bovine colostrum before and after heat treatment and bovine plasma. Concentration of IgG was quantified using a commercially available RID kit and a modified ELISA. Samples of bovine colostrum and plasma were collected from individual animals and colostrum was tested before and after heat treatment at 60°C for 30 min. All samples were tested using both methods. Pearson correlation coefficients were determined for RID and ELISA values from unheated colostrum, heat-treated colostrum, and plasma samples. Mixed models were used to determine the effect of assay on IgG measurement in colostrum and plasma and effect of heat treatment on IgG concentration in colostrum. A weak correlation was found between ELISA and RID results in plasma and unheated colostrum. Concentration of IgG was significantly lower in all sample types when measured by ELISA compared to RID. Thus, direct comparison of ELISA and RID results is not recommended. Colostrum IgG concentration significantly decreased after heat treatment as measured by ELISA, but means were not different when measured by RID. Correlation plots between colostrum values measured before and after heat treatment indicated changes in the colostrum protein matrix due to heat affected RID and ELISA assays differently. This investigation compared RID and ELISA results, but no conclusions could be drawn as to the accuracy of either assay.

Comparison of single radial immunodiffusion and ELISA for the quantification of immunoglobulin G in bovine colostrum, milk and calf sera

“…Therefore, the application of a new cut-off value may enable comparison between kits; however, this would have to be empirically determined through further validation. This recommendation is in agreement with research by Gelsinger, Smith, et al (2015), who reported that colostrum and plasma samples had significantly lower IgG concentration when measured by ELISA method compared to sRID. Colostrum IgG values determined by sRID were almost twofold that of ELISA; however, plasma values determined by sRID were only 1.3 times greater than values determined by ELISA method.…”

“…In the present study, a strong correlation was observed between the sRID and the ELISA method. In contrast to our findings, Gelsinger, Smith, et al (2015) reported a weaker relationship between a modified ELISA (Bethyl Laboratories, Montgomery, TX, USA); and the protocol described by Vetter et al (2013), and a commercially available sRID assay (Triple J Farms, Bellingham, WA, USA) when measuring colostrum (R 2 = 0.36; P = .01) and plasma IgG concentrations (R 2 = 0.59; P < .01), although these were still significant. The differences observed between these studies may be specific to the particular kits that were used.…”

“…However, it is an expensive and time-consuming test, requiring an incubation period of 18-24 h. In contrast, ELISA method has a higher throughput, is less costly and analysis can be completed in a much shorter time (Lee et al 2008). Consequently, recent research has used ELISA method to quantify IgG levels in colostrum, plasma and sera (Vetter et al 2013;Baumrucker and Bruckmaier 2014;Gelsinger, Smith, et al 2015).…”

Separation of immunoglobulins from colostrum using methods based on salting-out techniques

“…The composition of BC changes rapidly after parturition. The concentration of IgG in BC can be over 50 g/l (Godden 2008;Vetter et al 2013), while the concentration of IgG in cow's blood serum varies from 2.6 to 38 g/l (Gelsinger et al 2015) and in mature bovine milk its content is in the range of 0.6 g/l to 1 g/l (O'Mahony & Fox 2013).…”

<b>Modelo de risco para mastite no pós-parto:</b> aspectos hematológicos e bioquímicos

“…Para produzir um litro de leite são necessárias 72 g de glicose . A captação de glicose para glândula mamária é mediada pelo GLUT1, GLUT8, GLUT12, SGLT1 e SGLT2 (DE KOSTER;OPSOMER, 2013 DETILLEUX et al, 1995;GOMES et al, 2011;VERWEIJ;KOETS;EISENBERG, 2014;GELSINGER et al, 2015).…”