Frequently Asked Questions – customized stable cell lines

  1. Which host cell lines do you provide?

    Our SCREENflex technology is based on different master cell lines of mammalian origin. You can choose between CHO (adherent/suspension) and/or HEK293 cells.

  2. Which genes can be expressed?

    There are no limits. We successfully established cell lines for our customers expressing GPCRs, ion channels, antibodies or cytokines. In addition, there is the possibility to design expression cassettes with more than only one gene driven by the same or different promoters. Moreover, we offer codon-optimized transgenes or generation of recombinant genes with tags for an easy convenient detection or purification.

  3. Why should I choose SCREENflex instead of conventional cell line development?

    Conventional strategies to establish stable cell lines are based on random integration of expression-vectors into the genome of the host cell. The chromosomal surrounding strongly influences both stability and expression level. Therefore, the isolation of a stable, high expressing cell line is a laborious procedure without guaranteed success. Our SCREENflex master cell lines harbor a tag within a single chromosomal loci that confers stable expression of a recombinant gene. To establish the desired customer cell line the tag is cut out and at the same genomic locus the gene of choice is pasted in by a DNA-recombinase (molecular cut-and-paste). Since the desired gene is pasted in at the same chromosomal locus and no other chromosomal regions are altered, all positive expression and growth features of the optimized master cell lines are transferred to the new customer´s cell line. For details please see also. more

  4. What are the time lines for the development of a stable expressing cell line?

    As the cell line development is based on our in-house master cell lines, the time required for the establishment is estimated to be about only one month.

  5. Are the resulting cell lines suitable for High-Throughput-Screening?

    Yes. And for many more applications…

  6. Do you have other cell lines than CHO or HEK293 for stable cell line generation?

    We can establish from any other cell line recombinant stable cell lines. The timelines will be longer for these projects. We suggest to discuss the optimal strategy together with the customer.

Frequently Asked Questions - immortalization

  1. How do you immortalize my primary cell material?

    The technology behind is based on the viral transduction of your primary cells with a gene bank which harbors a composition of different immortalizing genes.

  2. Do you know which genes are integrated?

    Yes. We analyze the gene integration pattern for every immortalized cell line so that the customer knows which genes are overexpressed.

  3. Are the genes delivered on separate vector constructs?

    The genes are on separate vectors. The backbone of these vectors is the same for all genes (so only the genes are different).

  4. Can you provide me with an approximate timeline for clonal immortalized cell line generation using your technology?

    Based on our experience the immortalization process takes 3-4 months. This means – depending on the cell type – that the cells show a robust and continuous proliferation. After the cell lines display a robust proliferation pattern, they can be frozen, shipped and/or characterized.

  5. What do I receive after you immortalized my cell line of choice?

    Here you have the option that we do both - the immortalization and a detailed characterization or that we merely perform the immortalization and provide you with the immortalized clones for further characterization.

  6. How many cells do you require for the immortalization process?

    The starting number does not need to be high. We have successfully immortalized primary cells for our customers starting with roughly 1*10e5 cells.

  7. If I would like to have a detailed quote for the generation of an immortalized cell line, which information should I provide?

    If possible, we desire the following information: Who provides the primary cells? Are the primary cells proliferating or frozen? Are they homogenous? Which culture media do the different cell types require?

  8. Does the immortalization technology work for all cell types?

    Based on our experiences with different cell types from different species, we are able to immortalize the primary cell of choice if the transduction efficiency is above 10 %. For this purpose, we additionally perform a transduction with a suitable reporter that allows us to easily monitor transduction efficiency. In case the transduction efficiency is below 10 % we would stop and try to improve transduction efficiency. We cannot guarantee that we can successfully establish each cell type.

  9. What is the biosafety level of the immortalized cells?

    All our cell lines fall into biosafety level 1.

  10. Could you provide some insights into the costs for cell line generation?

    The immortalization of primary cell material will be approximately 10-20.000€. If we are talking about immortalization and characterization it will be about 30-80.000€.

  11. How are the license conditions if you immortalize a cell line for us?

    For internal use customized immortalized cells are royalty free. You can use the cells also for commercialization purposes providing that you do not sell these cells directly. The royalties would depend on the service that you plan to offer.


Cell-type specific protocolsPDF
CI-huAEC Human Airway Epithelial cellsView PDF
CI-hAELVi Human Alveolar Epithelial cellsView PDF
CI-huChon Human ChondrocytesView PDF
CI-huFIB Human FibroblastsView PDF
CI-huMEC Human Microvascular Endothelial cellsView PDF
CI-huOB Human OsteoblastsView PDF
CI-huVEC Human Umbilical Vein Endothelial cellsView PDF
CI-huThyrEC Human Thyroid Epithelial cellsView PDF
CI-muADINTESTI Murine Adult Intestinal Epithelial cellsView PDF
CI-muINTEPI Murine Intestinal Epithelial cellsView PDF
CI-muMEC Murine Microvascular Endothelial cellsView PDF

Stay in touch