Novel lipophilic tracking dyes for monitoring cell proliferation.

The advent of contemporary digital instrumentation has enhanced both the potential and the complexity of flow cytometric experiments, allowing for the detailed dissection of immune cell subsets and their functions. The use of cell tracking labels such as PKH26 and CFSE has been important in observing such cellular functions, but their visible emission characteristics have limited the design of such analyses. As the demand for multiparametric flow cytometry intensifies, it will become increasingly important to utilize a broader range of cell tracking reagents to optimize the measurement of fluorescence signals and to provide flexibility in the use of commercially available fluorochrome - antibody combinations. We report on the evaluation of three lipophilic membrane dyes, CellVue Lavender, CellVue Plum and CellVue NIR780; with fluorescence emissions in the violet, far-red and near infrared wavelength regions, respectively. These reagents are similar to established tracking dyes such as PKH26 and CFSE in terms of staining procedure, membrane stability, optimal concentration, and lack of effect on cellular proliferation. The CellVue dyes however, exhibit different spectral characteristics than existing tracking compounds, and capitalize upon the increased number of lasers incorporated into commercially available instrumentation; thus permitting measurement of labeled populations in underexploited regions of the spectrum.