Multiple Cell Populations When Expecting Single Population

Symptom

Flow cytometry plots display two or more distinct cell populations where only one homogeneous population was expected. A second population often appears at approximately twice the fluorescence intensity of the primary population.

1. 1 Cell doublets (aggregates of two cells) present in sample, appearing as population at approximately 2x fluorescence intensity
2. 2 Multiple cell types present in heterogeneous sample, each expressing target protein at different levels
3. 3 Inadequate cell separation or purification before staining, leaving mixed populations

1. 1 Mix cells gently using pipette before staining and again immediately before running on cytometer to dissociate doublets
2. 2 Filter cells through 30 μm nylon mesh to remove clumps and doublets
3. 3 Check expected expression levels from all cell types in sample; perform adequate cell separation using isolation kits if necessary; use FSC-A vs FSC-H or SSC-A vs SSC-H gating to identify and exclude doublets during analysis

Related Video (3)

Bilibili (China-Accessible Mirrors) ★ 85

Flow Cytometry Complete Workflow: Sample to Analysis

"Complete flow cytometry workflow with explicit troubleshooting section directly addresses sample preparation and result analysis where doublet artifacts arise"

Bilibili (China-Accessible Mirrors) ★ 78

Ten-Minute Guide to Flow Cytometer Instrument Operation

"Demonstrates gating, scatter plots, and histogram interpretation—essential skills for identifying and distinguishing doublet populations from singlets"

Bilibili (China-Accessible Mirrors) ★ 72

BD FACSAria Flow Cell Sorter Practical Operation

"Live demonstration of BD FACSAria sample preparation and sorting setup shows practical methods for reducing cell aggregation during instrument operation"