BeaverBeads GSH Magnetic Beads for GST Fusion Protein Purification

Product Overview

BeaverBeads™ GSH are superparamagnetic agarose microspheres presenting immobilised glutathione, the natural ligand of glutathione S-transferase. They capture GST-tagged recombinant proteins directly from crude lysate and release them under mild, non-denaturing conditions with free reduced glutathione — a single-step purification that preserves the biological activity of the target.

Because separation is magnetic, the workflow avoids the steps that make column chromatography slow: no high-speed clarification of the crude sample, no filtration, no flow-rate control and no chromatography hardware. The manufacturer reports that a skilled operator can obtain highly purified protein in under one hour, and that parallel processing of many samples scales without additional equipment.

Binding capacity and performance

Up to 10 mg of GST fusion protein bound per mL of beads. Capacity is quoted against 100% beads; the product is supplied as a 10% (v/v) suspension, so 1 mL of suspension contains 100 µL of beads. Actual capacity depends on the size, folding and accessibility of the GST fusion partner, so the manufacturer states this as a reference value rather than a guarantee.

Purification workflow

Binding and washing use Buffer A (140 mM NaCl, 2.7 mM KCl, 10 mM Na₂HPO₄, 1.8 mM KH₂PO₄, pH 7.4). Elution uses Buffer B (50 mM Tris-HCl with 10 mM reduced glutathione, pH 8.0), prepared fresh because reduced glutathione oxidises readily. Tightly bound fusions can be recovered by extending the elution time, repeating the elution, or raising the glutathione concentration.

Beads are then regenerated: alternating high-pH (0.1 M Tris-HCl, 0.5 M NaCl, pH 8.5) and low-pH (0.1 M sodium acetate, 0.5 M NaCl, pH 4.5) washes for light use; 6 M guanidine hydrochloride followed by PBS to strip denatured or precipitated protein; 70% ethanol or 0.1% non-ionic detergent to remove hydrophobic contaminants.

Applications

Purification of GST-tagged recombinant proteins from bacterial, insect and mammalian expression systems; GST pull-down assays for protein–protein interaction mapping; immunoprecipitation using GST-fusion bait; and purification of glutathione transferases and other glutathione-binding proteins. Suitable for both research-scale and process-development work, manually or on automated magnetic workstations.

Handling and safety

Do not freeze, dry out or centrifuge the beads — each causes irreversible aggregation. Resuspend fully before every use. A magnetic separator is required. Prepare the glutathione elution buffer immediately before use. Keep beads and separators away from metal objects, electronic devices and implanted electronic devices such as cardiac pacemakers.

For Research Use Only. Not for use in diagnostic or therapeutic procedures. Specifications are those published by the manufacturer, BEAVER Biomedical Engineering Co., Ltd.