Our Take
D&D-seq solves a real bottleneck in single-cell genomics, but it is a new technique published once in Cell, not yet deployed in clinical pipelines or validated at scale by independent labs.
Why it matters
Transcription factors are becoming therapeutic targets in oncology and gene therapy. Tools that reveal how regulatory proteins actually behave in patient cells, rather than inferred indirectly, will drive better target validation and drug screening workflows.
Do this week
If you profile regulatory proteins in primary patient samples: request early access to D&D-seq through academic collaborators at Weill Cornell or similar centers before committing new budget to bulk ChIP alternatives.
Base editing captures transient protein binding in single cells
Researchers at Weill Cornell have published a method called D&D-seq (docking and deamination followed by sequencing) in Cell that directly detects where transcription factors and other regulatory proteins bind DNA in individual cells. The approach fuses a cytosine base editor to an antibody-binding nanobody, allowing the enzyme to mark DNA at protein-contact sites with a C-to-U edit. Those edits create a stable molecular record readable by sequencing.
The method captures interactions that traditional bulk assays like ChIP-seq and CUT&RUN often miss, particularly weak and transient contacts. Critically, D&D-seq works inside standard single-cell workflows. The authors demonstrated integration with scATAC-seq, ATAC-seq, and whole-genome sequencing, allowing researchers to map protein binding, chromatin accessibility, gene expression, and genetic variation within the same cell.
The team profiled CTCF binding in primary T cells carrying IDH2 mutations found in leukemia, exposing cell-to-cell heterogeneity in regulatory wiring that bulk methods typically mask.
Single-cell regulatory maps unlock mutation and drug response studies
Existing methods for profiling transcription factor binding at single-cell resolution rely on indirect inference: gene expression signatures or motif analysis of open chromatin peaks. These approaches identify probable binding sites, not actual ones. D&D-seq provides direct evidence of protein-DNA contact in the same cells used for other measurements.
As transcription factors move from basic research into therapeutic development, the ability to monitor how mutations, drugs, and engineered perturbations reshape regulatory landscapes at single-cell resolution becomes essential. Patient-derived cells can now be profiled for how a drug candidate alters transcription factor binding and chromatin state simultaneously, collapsing timelines for target validation and off-target detection.
The platform-agnostic design means labs need not choose between protein binding, accessibility, and expression—they can acquire all three in the same experiment.
Check compatibility with your existing single-cell infrastructure
D&D-seq is not yet a commercial kit and has not been reproduced by independent groups outside Weill Cornell. If your lab profiles regulatory proteins in primary or diseased samples, monitor publications for validation at other centers and requests for beta access through academic partnerships. The method's ability to pair binding maps with expression and chromatin data in the same cell makes it worth staging into protocols, but do not replace existing ChIP or CUT&RUN pipelines until reproducibility reports emerge from at least one other institution.