Background Spread Due to Spillover Not Corrected

Symptom

Even after compensation, background spread from spillover effects makes it difficult to determine appropriate gate boundaries. Positive and negative populations are not clearly separated in the detector of interest.

1. 1 Compensation removes spillover signals but does not correct background spread caused by spillover
2. 2 FMO (fluorescence minus one) controls not used to determine background from other fluorochromes
3. 3 Gate boundaries set without understanding cumulative background from all other channels
4. 4 High background from multiple fluorochromes accumulating in the target detector

1. 1 Use FMO controls with all antibodies in the panel minus the one being measured to determine background spread
2. 2 Prepare FMO control for each detector where gate boundary is difficult to establish
3. 3 Analyze FMO data to understand background contribution from all other fluorochromes in the target detector
4. 4 Set appropriate gates based on FMO control data showing cumulative background effects

Related Video (2)

BD Biosciences ★ 90

Flow Cytometry Compensation Tips and Tricks

"Directly addresses spillover and compensation issues, explaining why compensation doesn't eliminate background spread and how to improve gating."

BD Biosciences ★ 70

Intro to Flow Cytometry

"Provides foundational understanding of flow cytometry principles, including fluorescence and spillover context needed to grasp the failure mechanism."