Rapid quantification of immunoglobulin G from plasma using affinity chromatography: partial validation of an efficient analytical method.

Affinity chromatography-based methods for immunoglobulin G quantification present an attractive alternative to widely used nephelometry due to their simplicity, speed, and compatibility with various sample types. This study validates the efficient analytical use of commercially available POROS CaptureSelect FcXP affinity resin, a stationary phase optimized for fast recombinant human IgG purification. The analytical method was validated in a simple bind-elute mode with a cycle time of 5 minutes. Linearity was confirmed in a range of 4 µg (lower limit of quantification) to 260 µg, allowing direct quantification of IgG from human plasma without further dilution. The method demonstrated excellent precision, with %RSD values ranging from 5% to 1% and satisfactory recovery 99% on average, respectively. By decreasing the residence time from 0.2 minutes to 0.1 minutes, a cycle time of 2.5 minutes was achieved, demonstrating a powerful chromatographic method for fast and reliable IgG quantification. This method offers significant advantages over nephelometry, including reduced analysis time and enhanced compatibility with high-throughput workflows.