Low IP Efficiency from Suboptimal IgG-Bead Binding

Symptom

IP shows weak target protein recovery despite adequate antibody concentration and protein expression. Bead pellet appears smaller than expected or shows poor antibody capture.

1. 1 Protein A beads used with mouse antibody (lower affinity for mouse IgG)
2. 2 Protein G beads used with rabbit antibody (lower affinity for rabbit IgG)
3. 3 Mismatch between bead type and antibody host species reduces capture efficiency

1. 1 Use Protein A beads when working with rabbit antibodies (higher affinity for rabbit IgG)
2. 2 Use Protein G beads when working with mouse antibodies (higher affinity for mouse IgG)
3. 3 Consider combination Protein A/G beads to increase IgG binding across species
4. 4 Optimize bead choice according to host species of IP antibody

Related Video (2)

Cell Signaling Technology ★ 75

Western Blotting Protocol

"CST Western Blotting protocol video shows the same antibody-bead and immunoprecipitation workflow where IgG-bead binding problems occur."

Cell Signaling Technology ★ 70

How CUT&RUN Profiles Chromatin | Cell Signaling Technology

"CST CUT&RUN animation explains antibody-bead capture and affinity considerations relevant to understanding suboptimal IgG-bead binding in IP."