Thiophilic adsorption or thiophilic chromatography is a routinely used technique for the low cost, simple purification of immunoglobulins. Thiophilic adsorption was first developed by Porath et al in 1984 and is a group specific, salt-dependent purification technique that has distinct affinity towards immunoglobulins and α2- macroglobulins. The thiophilic adsorption works on the principle that some proteins in high salt are able to bind to an immobilised ligand that contains a sulfone group in proximity to a thioether group. The bound proteins are then eluted in decreasing salt concentrations. The thiophilic resin binds immunoglobulins, including IgG, IgY and IgM, from serum, ascites or tissue culture supernatants and the purified immunoglobulins are then eluted in a near neutral aqueous buffer.

The thiophilic resin has a high binding capacity (~20 mg/ml human IgG/ml resin) and a broad specificity for various immunoglobulin molecules. Thiophilic adsorption has been used to purify other proteins including horseradish peroxidase, glutathione peroxidase, lactate dehydrogenase and allergens.