Footprint-Free™ gene editing for even the most difficult cell types

Transposagen uses the proprietary Footprint-Free™ gene editing system to make precise single nucleotide changes and insert new genes. This process uses a removable selection cassette to enrich for cells with rare editing events, removing the burden of screening thousands of clones to find the correct edit without the restriction of leaving behind selection debris in the genome. Other systems, including ssODNs and Cre/LoxP, leave behind traces in the genome which may impact interpretation of results.

The rise of Footprint-Free™ gene editing

Footprint-Free™ gene editing is a completely removable selection system, making the process possible in a variety of difficult cell lines. Gaining acceptance amongst researchers for optimization of gene editing procedures, recent studies have shown Footprint-Free™ gene editing to be successful when combined with CRISPR-Cas9 and XTN™ TALENs to facilitate gene corrections in human iPS cells mutations for cystic fibrosis, β-thalassemia, and HIV.1-3.

How Footprint-Free™ gene editing works

  1. Homologous recombination is stimulated at the target site using site-specific nucleases such as CRISPR or XTN™ TALENs.
  2. The piggyBac™ plasmid, with selection cassette and desired gene edits, is integrated into the genomic DNA.
  3. After selection, Excision Only piggyBac™ (PBx) precisely removes the selection cassette, leaving pristine edited genomic DNA with no scarring.

Graphic: How it works

Gene Knockin

The advantages of Footprint-Free™ gene editing

  • Positive & negative selection
  • Scarless selection cassette removal
  • Nuclease compatible with ZFN, XTN™ TALEN, CRISPR, and more
  • Works in difficult cell lines
  • Reduced screening times
  • Shorter timeline & full customization

How to bring Footprint-Free™ gene editing to your lab

DIY Development

Order off-the-shelf (OTS) reagents or let us build custom reagents specifically for your project. We are dedicated to delivering the highest quality products for efficient, cost-effective gene editing solutions

Customized Cell Engineering

Let us take on the heavy lifting when it comes to cell line engineering. Using our suite of technologies, including piggyBac™, we can engineer all types of gene edits—knock-outs, knock-ins, transgenic edits, and more. Working closely with our scientists, our lab becomes an extension of yours.


Bring the piggyBac™ system to your company as a platform for R&D and commercial use. Contact us to learn more about our licensing opportunities.

Products and pricing

Engineered cell line, specific gene knock-in, or gene edit

Catalog #: KIcell

For a detailed description of this service, and accurate pricing, please contact us for a customized quote. Timelines and pricing will depend on complexity of gene edit and cell type. Estimated delivery of single cell clones is approximately 6-9 months.