Fig. 5

Initial frequency distribution of plasmids encoding each sgRNAs in the library. An example of a typical distribution (in our experience) is shown, in terms of the spread of frequencies. During the chemical synthesis of oligos encoding each sgRNA in the library, there is variation in the initial frequency of each oligo and this is library-specific. The frequency distribution of a library used by a specific researcher can be determined empirically by next-generation sequencing of the plasmid library prior to conducting the screen