• TARGATT™ Technology For Site-Specific Knock-In
    • TARGATT™ HEK293 and CHO Cells
    • CHO Cells for Bioproduction
    • Custom Services and Off-the-Shelf Products
    TARGATT™ Technology For Site-Specific Knock-In

TARGATT™ HEK293 and CHO Cell Protein Expression

TARGATT™ technology enables the site-specific integration of any gene-of-interest (GOI; up to 20kb) at a preselected safe harbor locus with the use of a unique integrase. Applied StemCell has generated many TARGATT™ cell lines, including the TARGATT™ CHO and HEK293 Master Cell Lines. These high-quality cells are now part of ready-to-use TARGATT™ knock-in kits that you can use to insert your GOI in your own lab. We have observed steady, medium to high levels of protein expression when using our master cell lines for customer projects, so you can confidently purchase any kit that best suits your research needs. Additionally, our experts have used engineered TARGATT™ cells to address common bioproduction issues.

The traditional CHO antibody and animal bioproduction methods are inefficient because they require random gene insertion and forced amplification of transgenes. Applied StemCell has addressed these problems by utilizing our expertise in cell line and animal model engineering with our proprietary TARGATT™ technology to develop two bioproduction methods: TARGATT™ CHO Master Cell Line and Transgenic TARGATT™ Rabbits. Both methods offer low cost, efficiency, consistent protein expression and high protein yield that is easily scalable for large-scale bioproduction.

Advantages of the TARGATT™ Master Cell Line:

  • High knock-in efficiency
  • Site-specific integration into the H11 genomic hotspot well-defined safe harbor locus
  • Single gene knockin: one variant - one locus - one cell line
  • Unidirectional integration for stable knock-in cell lines
  • Uniform, high-level gene expression
  • Overcomes challenges such as random insertion, gene silencing, multiple copy gene integration, ablated gene expression.
  • TARGATT™ CHO and HEK293 Master Cell Lines
  • Transgenic TARGATT™ Rabbits for Bioproduction

If you would like to work with your own cell line, our experts can engineer the TARGATT system into your cell line. To learn more, explore our Custom TARGATT Master Cell Line Generation page or contact us today to schedule your free consultation.

Service Options

Bioproduction - CHO Cells

Bioproduction: CHO Cells

TARGATT™ CHO Cells for Recombinant Protein and Antibody Bioproduction!

Bioproduction: CHO Cells

TARGATT™ HEK293 Master Cell Line For Site-Specific Knock-in

TARGATT™ HEK293 Master Cell Line For Site-Specific Knock-in

TARGATT™ HEK293 Master Cell Line and Knockin Kit - A valuable research tool to generate stable knock-in cell lines.

TARGATT™ HEK293 Master Cell Line For Site-Specific Knock-in

TARGATT™ Rabbit for Biopharming

TARGATT™ Rabbit Bioproduction

TARGATT™ Rabbit for Biopharming and High-Yield Recombinant Protein and Antibody Production

TARGATT™ Rabbit Bioproduction






Products and Services
Application Notes

CHO Bioproduction

CHO Bioproduction Service

  • Safe-Harbor Locus: H11 (non-optimized locus)
  • Proteins Expressed: Two therapeutic antibodies, Ab1 and Ab2
  • Copies Inserted: 1 (single copy)
  • Production Parameters:
    • 17-day fed-batch shake-flask
    • Bulk enriched pools (no single-cell cloning)
  • Yield: ~1 g/l


  • Bioproduction in rabbit milk
  • TdTomato proof-of-concept
    • Tdtomato Molecular weight = 56 kD
    • Factor VII molecular weight = 52 kD
  • F1 heterozygous rabbit (1 copy)
  • Yield: 18g/l in homozygous rabbits
Support Materials


TARGATT™ Technology For Antibody Discovery and Screening

(March 2021)

*Featured in Informa Connect's eBook: Antibody
Discovery, Selection & Screening

  • Chi, X., Zheng, Q., Jiang, R., Chen-Tsai, R. Y., & Kong, L. J. (2019). A system for site-specific integration of transgenes in mammalian cells. PLOS ONE14(7), e0219842.