At the Hanson-Wade  CRISPR Bioinformatics meeting, in Cambridge, February 26, Thomas S. Cradick, Director of the Protein Engineering Laboratory at the Georgia Insitute of Technology and a member of the Gang Bao lab, presented a review of CRISPR/Cas9 targeting activity. He focused on RNA-guided Cas9 nucleases and the frequency of resulting insertions and deletions in re paired DNA  and reviewed requirements for  bioinformatics support in choosing guide RNAs and determination of off-target cleavage sites.

An earlier  paper in which he is an author, addressing one aspect of CRISPR targeting, appeared in Nucleic Acids Research, 2014.

Nucl. Acids Res.-2014-Lin-nar_gku402

CRISPR off target Nucl. Acid


The paper underscores the need to “search partially matched sequences including base mismatches, deletions and insertions and their combinations in identifying off-target sites. Since there might be a large number of potential off-target sites due to the many partially matched sequences, and the effect of sgRNA–DNA sequence differences on off-target cleavage….”


Authors: Yanni Lin1, Thomas J. Cradick1, Matthew T. Brown1, Harshavardhan Deshmukh1, Piyush Ranjan2, Neha Sarode2, Brian M. Wile1, Paula M. Vertino3, Frank J. Stewart2 and Gang Bao1,*
1Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA, 2School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA and 3Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA

© The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.

(Among his many other papers, Cradick is an author with Feng Zhang  in Patrick D Hsu et al’s  “DNA targeting specificity of RNA-guided Cas9 nucleases” appearing in Nature Biotechnology in 2013)

This is a presentation he made at a Georgia Tech bioengineering symposium on design and engineering of engineered nucleases focused on pre-CRISPR   TALENS and Zinc Finger Nucelases.