(A) A schematic overview of the sgRNA scaffold. The linker between stem loops one and two was truncated to a single U nucleotide, whereas the incidence of strong internal gRNA interactions within stem loop 1 was abrogated by introducing a canonical A54:U60 nucleotide substitution. The combination of these two mutations show robust tolerance for the scaffold to be modified. The F-E modified scaffold (d) comprising an extended repeat:anti-repeat region and tetraloop also shows comparable effects on indel formation frequency [42]. (B) The frequency of indel formation following the introduction of these mutations shows a negligible mutator effect. To access the data, click or select the words “Appendix 1.”