How do I choose between the various Edit-R Cas9 expression plasmids?

To select one of the Edit-R Cas9 expression plasmids, consider the following: 1) If you prefer to select Cas9-expressing cells using Blasticidin, and the human CMV promoter is active in your cells of choice, you can choose the Cas9 nuclease expression plasmid with BlastR mammalian antibiotic selection marker (Dharmacon Cat #U-001000-120). 2) If you have access to a FACS instrument and prefer to sort cells based on expression of a fluorescent marker, you can choose one of six SMARTCas9-mKate2 nuclease expression plasmids. Because the SMARTCas9-mKate2 nuclease expression plasmids are offered with a choice of six different promoters, you must choose one based on known promoter activity in your cells of choice. 3) If you do not have access to a FACS instrument, or you simply prefer to carry out antibiotic selection via Puromycin treatment, you can choose one of six SMARTCas9-PuroR nuclease expression plasmids. Since these are also offered with a choice of six different promoters, you should choose the one with an active promoter in your cells.