Controlled delivery of β-globin-targeting TALENs and CRISPR/Cas9 into mammalian cells for genome editing using microinjection

Sci Rep. 2015 Nov 12:5:16031. doi: 10.1038/srep16031.

Abstract

Tal-effector nucleases (TALEN) and clustered regularly interspaced short palindromic repeats (CRISPR) with CRISPR-associated (Cas) proteins are genome editing tools with unprecedented potential. However, the ability to deliver optimal amounts of these nucleases into mammalian cells with minimal toxicity poses a major challenge. Common delivery approaches are transfection- and viral-based methods; each associated with significant drawbacks. An alternative method for directly delivering genome-editing reagents into single living cells with high efficiency and controlled volume is microinjection. Here, we characterize a glass microcapillary-based injection system and demonstrate controlled co-injection of TALENs or CRISPR/Cas9 together with donor template into single K562 cells for targeting the human β-globin gene. We quantified nuclease induced insertions and deletions (indels) and found that, with β-globin-targeting TALENs, similar levels of on- and off-target activity in cells could be achieved by microinjection compared with nucleofection. Furthermore, we observed 11% and 2% homology directed repair in single K562 cells co-injected with a donor template along with CRISPR/Cas9 and TALENs respectively. These results demonstrate that a high level of targeted gene modification can be achieved in human cells using glass-needle microinjection of genome editing reagents.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • CRISPR-Cas Systems*
  • Cell Line
  • Endonucleases / genetics*
  • Gene Expression
  • Gene Targeting*
  • Gene Transfer Techniques
  • Genetic Engineering*
  • Genome*
  • Humans
  • INDEL Mutation
  • K562 Cells
  • Microinjections* / methods
  • Mutagenesis, Insertional
  • Single-Cell Analysis
  • beta-Globins / chemistry
  • beta-Globins / genetics*

Substances

  • beta-Globins
  • Endonucleases