Stem cell biotechnologies


Yacine Laâbi: “Stem cells biotechnlogies” Lab head (CECS)

Pascal Fragner: Research engineer (CECS)


Aims and background:

Our research and development programs are organized into 3 main activities:

Biobanking of human Embryonic Stem (hES) cell lines

I-Stem’s biobank is a storage facility of a collection of hES cell lines either derived from normal embryos or embryos carrying specific genetic mutations and therefore represents an important resource for I-Stem’s research programmes.

Cell culture automation of human Pluripotent Stem (hPS) cells and their progenies

Due to the large number of hES cells and human induced Pluripotent Stem (hiPS) cells needed by I-Stem’s research groups, the development of large-scale culture systems for expansion and differentiation of those cells is critical. Our goal is to implement the process transfert of a number of bench-scale manual cell culture protocols developed and optimized at I-Stem to an entirely automated cell culture platform which will enable more reproducible procedures and provide critical savings on technical time and costs.

Genomic engineering of hiPS cells

Gene targeting by homologous recombination in hiPS cell has proven difficult. Introduction of DNA double-strand breaks by site-specific endonucleases called meganucleases is being successfully used to target endogenous genes in human cells. We are currently involved in a collaborative research programme with Cellectis biotech company aiming at genetically modifying hiPS cells in order to optimize differentiation protocols into particular cell lineages and allow the isolation of homogenous cell populations of interest.


Strategy, means and methods:

Biobanking of hES cell lines

Our duty is to thaw hES cell lines, amplify them at low passages, subject them to thorough quality control assays before freezing them by vitrification. The banking process is run under a rigorous quality management system allowing process standardization and traceability of the samples.

Cell culture automation of hPS cells and their progenies

Our group will be responsible for an entirely automated cell culture platform, the CompacT SelecT devoted to the amplification of hES and hiPS cells and their differentiation into various cell lineages.

Genomic engineering of hiPS cells

Meganuclease-mediated integration of two constructs aiming at monitoring the differentiation of hiPS cells into keratinocytes will be performed. Genetically-modified hiPS cells will be consequently differentiated and resulting keratinocytes selected by the expression of the integrated reporter gene.

hPS cells bioprocessing at I-Stem


Results and future prospects:

Biobanking of hES cell lines

I-Stem’s biobank contains a total of 38 hES cell lines covering 14 monogenic diseases: 19 were imported from foreign laboratories and 19 were derived in France (Tropel et al, 2010). Our bank holds 3186 cryotubes containing hESC that passed rigorous quality control procedures. The bank was authorized by the “Agence de la Biomédecine” and operates under international banking guidelines. The 19 hES cell lines derived in Strasbourg and banked at I-Stem are registered in the European Registry (hESCREG).

Cell culture automation of hPS cells and their progenies

Significant advancements have been made in the bioprocessing of hPS cells including the formulation of new cell culture media, the development of extracellular and acellular matrices that can replace feeder cells, the development of new enzymes for passaging and the discovery of small molecules that significantly enhance the survival and clonogenicity of dissociated cells, allowing single cell cryopreservation. These advancements will serve in the optimization of automated cell culture processes.

Genomic engineering of hPS cells If we are successful in implementing homologous recombination using the meganuclease technology in hiPS cells, other gene constructs will be considered: gene promoters controlling the expression of a reporter will allow us to guide and monitor the differentiation into specific lineages and to isolate homogenous populations of progenitor cells, master regulatory genes that will enforce the commitment and differentiation into specific lineages, markers that could be used for high throughput screenings.



  • Tropel P et al;, High-efficiency derivation of human embryonic stem cell lines following pre-implantation genetic diagnosis. In Vitro Cell Dev Biol Anim. 2010;46(3-4):376-85.
  • Lefort N et al., Human embryonic stem cells and genomic instability. Regen Med. 2010; 4,6,899-909.

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