# Anionic Detergents as Eluents for Microscale Isolation of Antigen-Specific Serum Immunoglobulins

## TL;DR

A new microscale method using anionic detergents gently isolates specific antibodies from serum, preserving their function and purity.

## Contribution

A novel microscale isolation method using anionic detergents for antigen-specific serum immunoglobulins is introduced.

## Key findings

- Sodium lauroyl glutamate (SLG) achieved up to 78.3% recovery of functional antibodies.
- The method retained 58.5–85.3% of antibody bioactivity after isolation.
- The workflow successfully isolated specific antibodies and total IgG with high specificity.

## Abstract

The detailed characterization of antigen-specific serum antibodies is hindered by the lack of efficient, gentle isolation methods. In this context, standard column affinity chromatography, although a powerful purification tool, presents practical challenges, including high antigen consumption and elution conditions that risk inducing antibody polyreactivity, while conventional acidic elution often compromises antibody integrity. This study introduces a novel microscale method for isolating specific immunoglobulins using anionic detergents as mild eluents. We employed antigen-functionalized hydrogel microarrays and magnetic beads as micro-immunosorbents. Among the tested detergents, sodium lauroyl glutamate (SLG) was optimal, achieving up to 78.3% recovery of functional antibodies. The optimized protocol, including recovery via G25-Sephadex gel filtration, effectively isolated specific antibodies from complex serum, retaining 58.5–85.3% of their functional bioactivity. Multiplex immunoassays confirmed the high specificity of the isolated antibodies and the lack of detergent-induced polyreactivity. The method was successfully adapted to isolate both specific antibodies (virus, dietary, and autoimmune) and total IgG, demonstrating versatility across platforms. This work establishes a robust, efficient, and gentle workflow for obtaining high-purity, bioactive antibodies, enabling their subsequent in-depth analysis for research applications.