Sometimes simpler is better: VLog, a general but easy‐to‐implement log‐like transform for cytometry

• Published in: Cytometry. Part A 2016-12, Vol.89 (12), p.1097-1105
• Main Authors: Bagwell, C. Bruce, Hill, Beth L., Herbert, Donald J., Bray, Chris M., Hunsberger, Benjamin C.
• Format: Article
• Language: English
• Subjects: Algorithms; biexponential; cytometry; Flow Cytometry; Humans; hyperbolic sine; Hyperlog; Logicle; Models, Theoretical; transformations; transforms; variance stabilization
• ISSN: 1552-4922; 1552-4930
• DOI: 10.1002/cyto.a.23017

The fundamental purpose of log and log‐like transforms for cytometry is to make measured population variabilities as uniform as possible. The long‐standing success of the log transform was its ability to stabilize linearly increasing gain‐dependent uncertainties and the success of the log‐like transforms is that they extend this notion to include zero and negative measurement values. This study derives and examines a transform called VLog that stabilizes the three general sources of variability: (1) gain‐dependent variability, (2) photo‐electron counting error, and (3) signal‐independent sources of error. Somewhat surprisingly, this transform has a closed‐form solution and therefore is relatively simple to implement. By including some quantitation elements in its formulation, the shape‐dependent arguments, α and β, usually do not require optimization for different datasets. The simplicity and generality of the transform may make it a useful tool for cytometry and possibly other technologies. © 2016 International Society for Advancement of Cytometry