Each vial contains a stable population of 1 million A549 cells expressing a green, red, orange, or NIR fluorescent protein restricted to the nucleus. Parental A549 cells were purchased from ATCC (Cat. No. CCL-185). A549 cells were transduced with the Incucyte^® Nuclight Green Lentivirus (Cat. No. 4475; EF1α, puromycin), Incucyte^® Nuclight Red Lentivirus (Cat. No. 4476; EF1α, puromycin), Incucyte^® Nuclight Orange Lentivirus (Cat. No. 4771; EF1α, puromycin) or Incucyte^® Nuclight NIR Lentivirus (Cat. No. 4805; EF1α, puromycin) at an MOI of 3 (TU/cell) in the presence of 8 µg/ml polybrene following the standard infection protocol. This resulted in ≥70% transduction efficiency. 48 hours post infection, the complete population of cells were grown for 3-5 days in complete growth media containing 1 µg/ml puromycin to select for cells expressing Incucyte^® Nuclight Lentivirus. Incucyte^® Nuclight Lentivirus expressing cells are maintained in complete media containing 0.5 µg/ml puromycin. Following selection, a panel of validation assays designed to evaluate the effects of nuclear label expression on functional cell biology was completed. These assays include comparisons of cell morphology, growth/proliferation, and migration between stable populations and the parent populations from which they were derived. In addition, all cells in our Incucyte^® Nuclight catalog have been certified mycoplasma free by ATCC.