Methodology for evaluating and comparing fluorescence measurement capabilities: Multi-site study of 23 flow cytometers
David R. Parks, Wayne A. Moore, Ryan Brinkman, Yong Chen, Danilo Condello, Faysal E. Khettabi, John P. Nolan, Stephen P. Perfetto, Doug Redelman, Josef Spidlen, Jonathan V. Dyke, Lili Wang, James C. Wood
We developed measurement methods and analysis procedures to perform inter-instrument comparisons and used them to evaluate and compare the fluorescence measurement capabilities among 23 cytometers in 9 laboratories selected to provide a range of instruments as well as multiple instances of similar instruments. The test suite included measurements on LED signals and on multi-level microparticles (beads) for photoelectron scale and background estimation and a set of 10 samples of stabilized reagent capture beads labeled with 10 different dyes. Our results demonstrate that inter-instrument comparisons can be carried out in a consistent and convenient way. The methodology presented in this paper can be the basis for creating an archive of such evaluations that would allow comparisons of new results from any instrument on which appropriate data could be acquired with previous results from a variety of different instruments. Considering the value and precision of LED signal evaluations, we recommend that new instruments include built-in LEDs and, ideally, controlled signal generators and software to provide easy evaluation of photoelectron scales.