Table 1. The percentage cost savings and the timelines using the CRISPR/Cas9 method compared with traditional homologous recombination technology in murine ES cells
mES cellsCRISPR (in zygotes)
conventional gene targetingindel (small deletion/insertion)deletionprecise editing (SNP)conditional KO (LoxP, FRT)Kl (reporter)
% cost savingsbaseline81%68%59%38%41%
avg. timelines12 months6.5 months7 months7 months8 months8 months
  • These estimates include project initiation through the N1 stage, at which germline transmission has been achieved and a genetically modified mouse strain has been established. The major difference between the costs and timelines reflects the necessity of performing electroporation, selection, clone picking, and the subsequent screening in mES cells for traditional gene targeting. Downstream phases (injections and subsequent breeding) are similar with respect to the timelines. Note that for conventional targeting for which there are no murine ES cells for the desired background strain, the project timeline will increase by an additional 6–18 months, depending on the extent of backcrossing required to move the mutation to the desired background strain.