Antibody Purification Reagents for Isolation, Cleanup and Enrichment

Both bind Fc regions of many IgG antibodies, but their affinity differs by host species and subclass. Protein G often has broader compatibility for some antibodies, while Protein A may be preferred for others. Check a species-and-isotype compatibility table for the exact reagent.

Protein L binds certain immunoglobulin light-chain families and can capture antibody fragments that lack an Fc region, provided they contain a compatible light chain. It is not universal, so antibody light-chain compatibility should be confirmed.

Low recovery can result from poor ligand compatibility, insufficient binding time, incorrect pH or salt, resin overloading, sample precipitation or incomplete elution. Measure antibody in the flow-through, washes and elution fractions to locate the loss.

It can reduce activity or promote aggregation for sensitive antibodies, especially with prolonged exposure. Collect into neutralization buffer promptly and test a milder or alternative elution strategy if activity decreases.

Purity depends on the ligand, starting matrix, washing and antibody format. Fc-affinity capture can remove many contaminants but may not eliminate aggregates, fragments or unrelated immunoglobulins. Additional polishing may be needed.

Purify and exchange it into a buffer compatible with the labeling chemistry. Remove interfering amines, thiols, azide or carrier proteins when required by the conjugation method.

Affinity capture followed by buffer exchange can remove many small molecules, but efficient removal should be verified. A dedicated desalting or dialysis step may be more predictable.

Measure concentration, purity and recovery, then confirm target binding or functional activity. Aggregate analysis, endotoxin measurement or sterility testing may be needed for sensitive downstream applications.