CE-based noncompetitive immunoassay for immunoglobulin G in bovine colostrum products

Area of Science:

• Analytical Chemistry
• Biochemistry
• Immunology

Background:

• Bovine colostrum is rich in immunoglobulins (IgG), crucial for neonatal immunity.
• Accurate quantification of IgG is essential for quality control of bovine colostrum products.
• Existing methods for IgG determination may be time-consuming or lack sensitivity.

Purpose of the Study:

• To establish a capillary electrophoresis (CE)-based noncompetitive immunoassay for IgG determination.
• To develop a rapid and sensitive method for quantifying IgG in bovine colostrum products.
• To optimize assay conditions for improved performance and reproducibility.

Main Methods:

• A noncompetitive immunoassay utilizing FITC-labeled protein G (FITC-PrG) and a mouse monoclonal antibody against bovine IgG.
• Formation of a sandwich immunocomplex (FITC-PrG-Ab-IgG).
• Separation and analysis of the immunocomplex by capillary zone electrophoresis (CZE) with laser-induced fluorescence (LIF) detection.
• Optimization using polyethylene glycol (PEG 20,000) in the running buffer to minimize adsorption.

Main Results:

• The CZE-LIF immunoassay provided rapid analysis (< 2 min).
• Addition of PEG 20,000 improved assay reproducibility and resolution by suppressing analyte adsorption.
• The method demonstrated good precision (5.1%), linearity (1-5 mg/L, r=0.9917), and a low limit of detection (LOD) of 0.1 mg/L.
• Successful application for IgG determination in bovine colostrum products with satisfactory results.

Conclusions:

• A robust and efficient CE-based immunoassay for IgG in bovine colostrum was successfully established.
• The developed method offers a rapid, sensitive, and reproducible approach for IgG quantification.
• This assay is suitable for quality control applications in the bovine colostrum industry.