PurKine™ Antibody Purification Kit (Protein A/G) (KTP2070) — Product Review & Buying Guide for Antibody Researchers

Protein A/G: The Hybrid IgG Binder That Covers the Subclasses Protein A Alone Cannot

If you purify monoclonal or polyclonal antibodies, you already know the Protein A vs. Protein G dilemma. Protein A binds human IgG1, IgG2, and IgG4 well but binds IgG3 poorly; in mice, it has the weakest affinity for IgG1. Protein G binds a broader range of mouse and human IgG subclasses but is more pH-dependent in its binding. Protein A/G is a recombinant fusion containing four Fc-binding domains from Protein A and two from Protein G — combining the broadest IgG subclass coverage with reduced pH dependence[reference:49][reference:50].

Abbkine's PurKine™ Antibody Purification Kit (Protein A/G) (KTP2070) packages this hybrid binder into a high-capacity, reusable, gravity-column-ready kit. Here's our detailed review.

What's in the Box?

A complete, ready-to-use kit with pre-formulated buffers.

Advantages

1. Broad IgG Subclass Coverage

The recombinant Protein A/G fusion contains four Fc-binding domains from Protein A and two from Protein G[reference:51]. It binds all human IgG subclasses and all mouse IgG subclasses — without binding mouse IgA, IgM, or serum albumin[reference:52]. This makes it a more general and convenient tool for investigating and purifying immunoglobulins than either Protein A or Protein G alone[reference:53].

2. High Binding Capacity

More than 7 mg human IgG per mL of resin[reference:54] — sufficient for routine monoclonal antibody purification from hybridoma supernatants and polyclonal antibody purification from serum.

3. Reduced pH Dependence

Protein A/G binding to immunoglobulins is not as pH-dependent as Protein A, and the recombinant Protein A/G is chemically modified with a proprietary method to minimize nonspecific binding of proteins[reference:55].

4. Reusable and Cost-Effective

No performance decrease after at least five repeated uses of the same batch of resin[reference:56] — critical for labs that purify antibodies on a routine basis.

5. Robust Flow Properties

The highly cross-linked 4% agarose beads tolerate linear flow rates up to 300 cm/h[reference:57], making the resin suitable for scale-up and rapid gravity-column runs.

6. Published Validation

This kit has been cited in 3 peer-reviewed publications, reflecting its adoption across antibody research and immunoassay development labs[reference:58].

Disadvantages

1. Gravity-Column Format

The kit is designed for gravity-column procedures at a variety of scales[reference:59]. Labs requiring FPLC/HPLC automation will need to explore Abbkine's bulk resin formats.

2. Research Use Only

Not intended for human or clinical diagnosis.

3. Not for IgM or IgA

Protein A/G does not bind mouse IgA or IgM, and does not bind serum albumin[reference:60]. If your target is an IgM or IgA antibody, this kit is not appropriate.

Who Should Buy This Kit?

✅ Buy this kit if you:

• Purify monoclonal or polyclonal IgG from serum, ascites, or cell culture supernatant
• Need broad IgG subclass coverage — including mouse IgG1, which Protein A alone binds poorly
• Want a reusable resin (≥5 cycles) for routine antibody purification[reference:62]
• Value pre-formulated binding/wash and elution buffers included in the kit
• Need high capacity (>7 mg human IgG per mL resin)[reference:63]
• Appreciate a kit with published validation (3 citations)[reference:64]

❌ Consider alternatives if you:

• Are purifying mouse IgM or IgA — Protein A/G does not bind these isotypes[reference:65]
• Require automated FPLC-scale purification — consider bulk resin or a different platform
• Need IgG subclass-specific purification (e.g., separating IgG1 from IgG3) — Protein A/G is a broad-spectrum binder, not a subclass-specific tool

Quick Specs Summary

📌 Reference Link: PurKine™ Antibody Purification Kit (Protein A/G) — KTP2070