Sci Rep. 2016 Dec 2;6:38198. doi: 10.1038/srep38198.
Improved bi-allelic modification of a transcriptionally silent locus in
patient-derived iPSC by Cas9 nickase.
Eggenschwiler R1,2, Moslem M1,2, Fráguas MS1,2, Galla M3, Papp O1,2,
Naujock M4, Fonfara I5,6, Gensch I1,2, Wähner A1,2, Beh-Pajooh A1,2,
Mussolino C7,8,9, Tauscher M10, Steinemann D11, Wegner F4, Petri S4,
Schambach A3, Charpentier E5,6, Cathomen T7,8,9, Cantz T1,2,11.
In order to help enforcing bi-allelic targeting with the new donor construct
, we reasoned that a dual-fluorescence approach using a combination of both,
eGFP- and DsRedEx-containing donors, might present a valid strategy.
Presence of two fluorescence markers within the same clone should indicate
that the corresponding cell line has integrated one fluorescence marker on
each allele. To this end, hPi cells were transfected with both donors and
Cas9_D10A nickase and AAT_g1 and AAT_g2 sgRNAs and selected using puromycin
followed by FACS sorting for the eGFP+, DsRed+ double positive fraction (Fig
. 3D).