Flow cytometry is a complex technology that is increasingly being used by clinicians to improve the quality of health care. In order to minimize artifacts and assure accuracy, rapid and simple quality control methods are critical for effective use of the technology in the clinical setting. Most clinical flow cytometric assays involve the acquisition of data from several tubes in order to accommodate many markers or stimulation conditions.

A common method of analysis involves the establishment of gates, based on parameters common to all tubes that can be uniformly applied across the entire panel, thus providing a basis for consistent population identification and minimizing time and effort in the data analysis process (e.g CD45/Side Scatter for Leukemia/Lymphoma immunophenotyping). The underlying assumption is that events are distributed the same way for each tube across the gating parameters. Violations of this assumption due to unanticipated and undetected shifts or other acquisition irregularities result in inaccurate phenotyping, potentially leading to inaccurate diagnosis.