Single-Stranded DNA with Internal Base Modifications Mediates Highly Efficient Knock-In in Primary Cells Using CRISPR-Cas9

Scientists showed that single-stranded DNA (ssDNA) with chemical modifications in 12–19% of internal bases improved knock-in by 2–3-fold compared to end-modified ssDNA in airway basal stem cells, CD34+ hematopoietic cells, T cells, and endothelial cells.