Site-specific gene modification usually uses homologous recombination (HR) of endogenous DNA with exogenous DNA. It stems from DNA homologous recombination technology (HR) in mouse embryonic stem cells (ESC), and has evolved to a new stage with the emergence of DNA nuclease-based gene-editing, including Zinc Finger Nuclease (ZFN), and more recent CRISPR/Cas9 technology. Compared with ZFN and TALEN, CRISPR/Cas9 technology is more efficient, shortens the timeline and reduces the cost of production, breaks species constraints, and also has the potential to directly edit genes in patient tissues.
Biocytogen developed an innovative CRISPR/Cas9-based Extreme Genome Editing — EGE™ — system, which is up-to 20-fold more efficient at knocking in large DNA fragments (> 5 kb) in the genomes of mice, rats and cell lines. EGE™ is successful for 98% of projects and therefore minimizes the timeline to generate genetically engineered animal and cell models.
|CRISPR/EGE™-based Gene Editing||High efficient; large gene knockout/knockin capabilities; simultaneously targets multiple genes; applicable to many species; easy to construct. Potential off-target effects (which can be reduced by choosing the appropriate sgRNA and eliminated by passaging); random insertion risks for gene knockin which can be screened by Southern blot.||Conventional KO mice/rats||6-8 months|
|Conditional KO mice/rats|
|ROSA26 locus gene KI mice/rats|
|Gene KI/ Mutation mice/rats|
|Normal cell lines KO/KI|
|hESC/iPS cells KO/KI|
|ESC/HR-based Gene Editing||Accurate, precise and reliably established, by far the only targeting technology which can meet the requirements of almost all genome modifications; but ES cells are required (only mouse cells are efficient for this technique), so it cannot be applied to other animal models); time consuming; heavy workload; high cost||Conventional knockout (KO) mice||7-11 months|
|Conditional KO mice|
|ROSA26 locus gene knockin (KI) mice|
|Gene KI/ Mutation mice|
|Transgenic Technology||Traditional transgenic technology is welcomed because the fast timeline low cost, super large fragment insertion, etc. But as the advance of new gene targeting technologies, especially EGE™, above advantages are not very obvious anymore. Especially random insertion, instability, large number founders can cost more time and money sometimes||Transgenic mice/rats||2-3 months for F0|
|Chromosome Engineering||Gene cluster replacement at the scale of megabase. Very special high technology for special application such as antibody gene cluster humanization.||Mouse||Very special high technology|
|Others Services||Besides the full-scale gene editing services, Biocytogen also provide milestone services relating with gene editing.||CRISPR plasmid construction; CRISPR activity assay; Donor plasmid construction|