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Cell engineering tools for transfection of sensitive cells

Compact TALEN™ are a new generation of TALEN™ (Transcription Activator-Like Effector Nucleases). Compact TALEN™ are monomeric modular DNA-binding proteins composed of a single TALE domain fused to the catalytic head of the nuclease I-TevI, designed to cut DNA double-strands in specific locations and enable efficient gene editing in sensitive cells (such as primary cells, plant cells, iPS cells and others).

How does monomeric Compact TALEN™ work?

Whereas our Custom TALEN™ requires the dimerization of two molecules, this new tool based on Cellectis bioresearch’s proprietary TAL effector nuclease technology, makes it possible to target specific DNA segments using a single molecule.

Compact TALEN™ are composed of a TALE domain and the catalytic head of I-TEVI enzyme fused to the N-terminus of the protein. This endonuclease works as a monomer, allowing Compact TALEN™ to work as a single molecule and introduce a DNA double-strand break at a specific target site (see below).

Available Compact TALEN™ validation levels

With Compact TALEN™, choose from our available levels of validation of TALEN™ activity or request a custom validation.
Do not hesitate to contact us to discuss your cell engineering project and to define together the best TALEN™ and validation level answering your needs.


Compact TALEN™ validation level


No validation

First human

Description Without any validation Standard validation in human cell lines
- Sequence specific mutagenesis activity on chromosomal target
- Deep sequencing
Deliverables 2 TALEN™ 2 TALEN™ + validation report
4 weeks 4 weeks**

* for immortalized cell lines
** additional 4 weeks for validation report


Overcome gene editing limitations

Easy and guaranteed


Efficient transfection of sensitive cells

Compact TALEN™ enables transfection of sensitive cells because of its requirement for only a small amount of DNA or RNA (~ 2.7 Kb, which is half of what is required for a Custom TALEN™)

Ease of viral vectorization

Monomeric Compact TALEN™ makes vectorization easier in viral shuttles

High specificity

Compact TALEN™ uses a partial DNA-specific endonuclease recognizing the DNA cleavage motif CNNNGN. This results in in vivo DNA cutting capability and specificity comparable with Custom TALEN™ results with a control for your proof of principle

To design an optimal Compact TALEN™ a sequence of 2 kb is required. For more information, please contact us.

Available data

The transfection of certain organisms or cell types can be difficult because of the size of the molecules and the quantity of nucleic acid required. This can be a particular problem with certain cell types including primary cells, iPS cells (induced pluripotent stem cells)  and ES cells (embryonic stem cells). Applications that use viral packaging for delivery can also cause problems – the material can be very expensive, and the size limitations in the viral payload can also make certain experiments impractical. This is where Compact TALEN™ can help.

(A) (B)

(A) Compact TALEN™ function in tobacco plant protoplasts to induce restoration of a YFP reporter through a single strand annealing assay. TALEN™ were targeted to a sequence fragment of the nptII gene (NPT5::FokI), Compact TALEN™ (TevI::cNPT6L) and negative control (Neg. Ctl). (B) Compact TALEN™ promote targeted gene disruption at endogenous loci in a mammalian cell line. CHO-K1 cells harbouring an integrated neomycin resistance gene were assayed with a TALEN™ (NPT5::FokI), Compact TALEN™ (TevI::cNPT6L) and negative control (Neg. Ctl) targeting NPT5 or cNPT6L, respectively.

The negative control in (A) and (B) does not carry the targeting sequence in the reporter construct.

Source: Beurdeley, M. et al. Compact designer TALENs for efficient genome engineering. Nat. Commun. 4:1762 doi: 10.1038/ncomms2782 (2013).



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