Non-specific Antibody Binding Creating Noise

Symptom

Antibody binds non-specifically to cells of interest, resulting in noisy data and elevated background. True marker expression cannot be distinguished from non-specific binding events.

1. 1 Test antibody exhibits non-specific binding to cell populations beyond target marker
2. 2 FMO controls cannot measure this background as they lack the antibody being studied
3. 3 Isotype control does not match the background characteristics of the test antibody
4. 4 Factors affecting background (antibody concentration, incubation time, Fc receptor binding) not controlled

1. 1 Use isotype controls matching the test antibody isotype and conjugated to the same fluorochrome to measure non-specific binding
2. 2 Ensure isotype control antibody concentration and conditions match the test antibody as closely as possible
3. 3 Recognize that isotype controls do not account for fluorescence spillover from other channels; use with compensation
4. 4 Run multiple control types during assay development to determine if non-specific binding is the main background source
5. 5 Consider optimizing antibody concentration, blocking Fc receptors, or adjusting incubation conditions to reduce non-specific binding

Related Video (3)

BioLegend ★ 75

Surface and Intracellular Cytokine Staining for Flow Cytometry

"Covers staining protocols including controls which directly address non-specific binding noise."

Cell Signaling Technology ★ 70

Tissue Controls & More for Immunohistochemistry | CST Tech Tips

"Discusses antibody controls and troubleshooting non-specific binding, directly applicable to flow cytometry."

BD Biosciences ★ 70

Cell Preparation for Flow Cytometry

"Provides cell preparation best practices that can help reduce non-specific antibody binding in flow cytometry."