Find the answer to your question concerning our services here. Our FAQs (frequently asked questions) are listed for the convenience of searching, ordering and using our products. If you have any other questions, please feel free to contact our scientific experts through the contact form or e-mail.

General FAQs

Project & Service

Who should I contact if I want to order a cell service / a protein service?

You can use our webpage contact form or write an email to contact@trenzyme.com. Our highly qualified scientific experts are looking forward to your inquiry and employ their extensive experience to complete your project successfully and efficiently.

Is there one specific project manager assigned for my project?

Yes, there is a specific project manager assigned to every project. Your project manager keeps you constantly informed throughout the project to ensure maximum success.

How often do I receive an update on the project progress?

You will receive weekly updates on the current process status and timeline of your project by your assigned project manager.

Do you also offer molecular biology services?

Yes, we offer molecular biology services, both as addition to our cell line development and protein production services and as stand-alone service.


How can I apply for a job or an internship?

You can use our application form on our career-website or write an email to job@trenzyme.com.

What are the typical tasks during an internship at trenzyme?

We discuss upfront the area you are most interested in and then propose the current options for you in detail.

What is the minimum duration for an internship at trenzyme?

The minimum duration of an internship is three months.

Cell Services FAQs

What quality control is carried out with the produced cell lines?

For all cell lines generated at trenzyme, a standard final quality check is carried out. This comprises thaw-viability assay and mycoplasma test. Additional analysis and an extended quality check including stability check are available.

I would like to order the generation of an assay cell line. How long does it take?

The timeline for the generation of a basic pool starts at 5 weeks and for clonal cell lines at 13 weeks.

What kind of analysis of the target expression do you offer?

Depending on the target and your specific requirements we can test the stable cell line for GOI expression by a variety of methods. You can choose from qPCR, Western blot, FACS analysis, ELISA, IF or cell-based assays.

What does the data sheet include?

The data sheet contains all relevant information regarding your cell line in a comprehensive and short version.

What does the report include?

We will generate a detailed documentation containing all project results and protocols as well as a detailed list of materials and substances (including lot numbers). You will obtain a draft version of the report for review. The report will be finalized after receiving your amendments (one round).

Stable Cell Line Development

Does the ExoIN technology work also for supension cell lines and adherent cell lines?

Yes, the ExoIN technology works for both adherent and suspension cell lines.

Which cell lines have you already worked with?

We already worked with dozens of human (e.g. HT1080, Jurkat,…) and non-human cell lines (e.g. NIH3T3, PC12,…).

Which methods do you use for generation of single cell clones?

Routinely we apply flow cytometry based cell sorting or limiting dilution for single cell cloning. For difficult target cell lines we also offer colony picking in soft agar.

What resistance markers are possible with your ExoIN technology?

For ExoIN technology we can offer puromycine, hygromycine and zeocin as possible resistance markers.

Which cell lines are available at trenzyme for generation of stable cell lines?

You can choose between our in-house cell lines HEK293 and CHO-K1 or you can send us your parental cell line of choice.

How does the ExoIN system work?

The ExoIN technology links target protein expression to the expression of a resistance marker on protein level. The target, the selection marker and the ExoIN module are transcribed together and initially a fusion protein is translated. This is cleaved co-translationally with highest efficiency, so your target is synthesized as free, non-modified protein.

Do amino acids remain on the target after cleavage with the ExoIN technology?

No, there are no additional amino acids remaining as the tag gets completely cleaved off. The target is unmodified after cleavage.

Does trenzyme only offer stable cell lines using ExoIN?

No, if you provide your preferred parental cell line and/or your expression system of choice, we will generate the recombinant cell line according to your needs.

Which tranfection method is used?

Our standard method is electroporation for the generation of stable assay cell lines, but lipofection or other chemical transfection methods are possible as well if required.

Does the datasheet contain a BSL classification of the cell line?

Yes, the data sheet contains a BSL classification, which depends on the target and parental cell line of choice (german Gen-TG).

Do you have experience with other expression systems?

Yes, we have a lot of experience with other expression systems. But we prefer our ExoIN system since it is the most powerful expression system with a lot of benefits.

Which promoter do you use for the ExoIN technology?

Our standard promoter is CMV but other promoters like EF-1 are also available.

Constitutive Expression

How many vials and how many cells per vial are delivered?

Our standard delivery comprises 3 cryovials per stable pool and 3 cryovials per each of the 3 best clones with 1e6 cells per vial for adherent cells or up to 1e7 cells for suspensions cells. Additional vials are possible on request.

Do royalties have to be paid?

The ExoIN cell lines are royalty free.

How many clones do you generate?

Our standard is to expand 30 and test up to 24 clones by the agreed method and deliver the best three clones according the analyses. If you have other requirements, we will discuss your needs and can adapt our standard service to a certain extent.

Does trenzyme offer stable cell lines off the shelf?

No, we offer only customized recombinant cell lines and actually no cell lines off the shelf.

Where is the ExoIN tag located (N- or C-terminus of the protein)?

The ExoIN tag is located at the N-terminus of the protein. Subsequent efficient cotranslational cleavage at the ribosome yields the desired free target protein unmodified and functional in a 1-to-1 stoichiometry with the selection marker.

Inducible Expression

What is the benefit of the ExoINDUCE system in comparison to other inducible systems?

The ExoINDUCE system works as an “one plasmid system” and all elements for the generation of an inducible cell line are located on one plasmid. Due to the elaborated design of the system and the proven selection strategy, there is no need to generate a regulator cell line first – the final inducible cell line can be generated in only one step saving a lot of time and money.

Which target classes have you already worked with?

We already worked with all different target classes: transmembrane receptors, channels & transporters, intracelllular proteins, secreted proteins and many other target classes.

Does trenzyme only offer the generation of stable, inducible cell lines using the ExoINDUCE system?

No, if you provide your preferred parental cell line and your inducible expression system of choice, we will generate the recombinant cell line according to your needs.

How does the inducible ExoINDUCE system works?

The regulation of the target expression in the ExoINDUCE system is under control of a proprietary version of the tetracycline transactivator (rtTA). It is an optimized “Tet-on” system, meaning the expression of the target is going to be induced by addition of doxycycline to the media.

GMP Production Cell Line Development

Which parental cell lines do you use?

We use Celonic’s CHOvolution® CHO-K1 and Thermofisher’s Freedom ExpiCHO-S™ as parental cell lines. Other cell lines on request.

What is the final productivity of the cell line after cell line development?

As a high standard productivity, we can reach up to 3g/l for mABs after cell line development. After process development, it can reach > 8 g/l.

Whicht type of license do you offer?

Within the cell line generation at trenzyme, a R&D license is already included and has not to be purchased. For any commercial application later on, a commercial license is needed.


Is a stability study being carried out?

We can optionally offer a stability study and also a copy number determination, if desired.

What additional service options are available for GMP production cell lines?

We can additionally offer development of the Downstream Processing (DSP), protein purification from fed-batch production and a variety of protein analysis services (e.g. mass spectrometry, protein sequencing, HP-SEC) as well as metabolite analyses during fed-batch small scale production.

What is the timeline for the development of CHOvolution® cell lines?

Our express version takes 16-20 weeks and includes two rounds of fed-batch-screening.

How do you validate the generated cell lines?

Depending on the target and your specific requirements we can analyze titer, cell growth properties, target gene copy number and stability as well as product quality.

Stem Cell Services

What kind of cells can be cultured, characterized or differentiated?

We work with all kind of human iPS cell lines (healthy, diseased, modified). Other stem cell types can be analyzed or differentiated on demand.

Is it possible to purchase iPSC lines or iPSC-derived progeny from trenzyme?

Although we do have internal iPSC lines and validated differentiation protocols, we do not sell these iPSC lines or iPSC-derived progeny.

Does trenzyme have validated internal differentiation protocols, which can be used to differentiated customer iPSC lines towards a special cell type?

Yes, we do have internal differentiation protocols (e.g. neuronal, or hepatocyte protocols), which can be used in order to provide customized iPSC-derived cells. You will receive the generated and cryopreserved cells, as well as a comprehensive data sheet, however, no details regarding the differentiation protocol will be given.

Stem Cell Differentiation 

How long does it take to generate an iPSC-derived cell type?

It’s depending on the cell type and the applied differentiation protocol. Together with our clients, we select a reliable differentiation protocol and define reasonable project milestones.

What kind of quality control is performed to ensure a successful differentiation?

We routinely perform immunofluorescence staining, FACs analysis and qPCR in order to characterize the stages of differentiation. For special read-outs, do not hesitate to contact our experts.

How can I get in touch during the realization of the project?

During the project, regular telephone calls, email correspondence and short reports ensure detailed exchange of information and results. Furthermore, technical discussions will help to implement key experiment layouts according to your needs.

Stem Cell Characterization

What general quality control is performed on the iPSC lines?

All iPSC lines are subjected to a standard set of quality control assays, investigating sterility, mycoplasma, viability, and morphology.

What kind of assays will be performed to functionally characterize the iPSC lines?

In order to characterize iPSC lines for the expression of pluripotency markers, immunoflourescence staining and/or flow cytometry for key pluripotency markers OCT4, SOX2, SSEA-4, TRA-1-60, and TRA-1-81 will be performed. Furthermore, the ability to form all three germ layers will be investigated via directed differentiation towards endo-, meso-, and ectoderm (immunoflourescence staining, RT-qPCR).

What kind of karyotyping will be performed?

In order to evaluate genomic stability, chromosomal abnormalities, and copy number variants, molecular karyotyping via Illumina BeadArray will be applied.

Cell Expansion

How do you cultivate the cells for the cell expansion service?

Depending on the cell line type, we use shake flask culture (suspension cell line) or cell stacks (adherent cell line).

Which cell numbers can you generate?

With our cell expansion service we can generate up to 1e9 cells in one batch.

Assay Service

What techniques do you use to measure endpoints?

We use a wide range of techniques to measure endpoints, e.g. FACS, Immunostaining, ELISA, Western blot and qPCR.

Based on which cell line types can you develop assays?

Our scientific experts can develop assays based on basic cell lines, customized cell lines or iPSC-derived cell types. For this, we use our in-house differentiation protocols with cardiomyocytes, hepatocyte-like cells or neurons for your analysis. Alternatively, you can provide us with your protocol so that after the technology transfer, our experts perform the work using this protocol internally at trenzyme.

Is it possible to order both, assay development and subsequent analysis of compounds?

Yes, our assay experts are delighted to develop an assay according to your needs prior to compound analysis.

Is there any limitation regarding the number of compounds that can be analysed?

We measure small and medium compound sets on a regular base. If larger sets need to be analysed, feel free to contact our assay experts.

Protein Services FAQs

How many custom proteins have you produced so far? What is the typical success rate?

We are working on recombinant proteins for more than 20 years and we have successfully produced more than 3000 different proteins so far. 

What is the concentration range of your proteins? How do you determine the quantity of them?

The concentration is mostly between 0.1 and 2 mg/ml but can be adjusted according to your needs. The concentration will be determined by either BCA, adsorption at 280nm or densitometric determination after Coomassie staining.

Can tags be cleaved off from recombinant proteins?

Yes, in most cases we use cleavable tag sequences. But cleavage efficiency can be influenced by the target protein and has to be tested.

What types of tags do you offer?

We use many different tags according to your needs. Very common tags for purification are the following: His, MBP, GST and Strep. But we use also different epitope tags or tags increasing the solubility or the localization of the target protein.

My protein should be glycosylated - which expression host do you recommend?

For the production of glycosylated proteins we offer expression in mammalian cell lines, Yeast and in Baculo system (insect cells).

I would like to order the generation of a protein. How long does it take?

Depending on the expression system and the purification process, the timeline for generating a protein is starting at 20 business days.

Are any preservatives added to my proteins?

No, generally we do not add preservatives to the proteins since they may influence the protein activity. But if you have a preferred storage buffer, we can use your buffer.

Does codon optimization guarantee better protein expression?

Yes, generally expression levels are higher after codon optimization. Therefore, we offer codon and DNA structure optimization within a project.

How will proteins be shipped?

Our standard priority shipment will be on dry ice. If required, we offer shipment on blue ice, at -20°C or even at room temperature (lyophilized proteins only) as well.

Are purification conditions native or denaturing?

Generally, we offer native purification conditions. Depending on target protein properties, denaturing purification can also be offered for proteins.

Are recombinant proteins and antibodies sterile?

We can additionally offer sterile filtration if you require this service.

Why does my protein show a higher (or lower) MW on SDS-PAGE or Western blot as calculated?

Posttranslational modifications like glycosylation or very rigid protein structures may have influences on protein properties and running behaviour. Sometimes proteins run higher, seldom lower and sometimes they run as a smear.

Guaranteed Protein Expression and Purification Packages

What do you guarantee within your Guaranteed Protein Expression and Purification Packages?

We guarantee the final success of the project – the yield, the purity and the timeline are guaranteed. You only have to pay if we deliver the protein.

What is included in the free feasibility check?

During initial free individual consulting, our scientific experts run a feasibility check (e.g. literature check, database check, product check, etc.) with your protein sequence to define the ideal service strategy for your specific target. The results will be discussed and you will receive a quote for the process proposed.

How do you decide if a target protein is applicable for a guaranteed package?

This will be decided by an initial feasibility check free of charge. Most important, the protein should be soluble and not a full length membrane protein. But the soluble domain of a membrane protein should work, for example.

What starting materials are required to begin a project?

We only need the amino acid sequence or uniprot reference number of your desired protein.

Which protein classes have you already expressed and purified?

We have successfully expressed all protein classes in different expression systems and different expression strategies.

What do I do if I cannot provide the template DNA for cloning? Is gene synthesis offered?

Yes, we offer molecular biology services like gene synthesis as addition to protein production services.

What deliverables will I receive upon completion of my project?

You will receive the purified protein including a datasheet. For more complex projects, you will also receive an additional and detailed report.

The purity of the protein should be higher than 75%. Is this possible?

Our minimum guaranteed purity is > 75% and in many cases we have > 95% by only one purficiation step. The final purity can be further increased by an additional purification step.

What is your guaranteed yield?

We guarantee the following minimal quantities: 3 mg for proteins produced by E.coli, 1 mg for labelled proteins produced by E.coli and 1 mg for proteins produced within a mammalian package. If a pilot study is included, guaranteed delivered amount can be extended.

Can you provide a corresponding antibody for a recombinant protein?

If you need both, your recombinant protein and a corresponding antibody, our guaranteed antibody package will be the best service choice for you.

My target protein should be glycosylated - which expression host do you recommend?

For generation of glycosylated proteins we offer different expression systems like Yeasts, insect cells (Baculo) or also mammalian cell lines. Depending on the nature of your target protein and your exact needs, we will propose the most suitable expression host and system for your project.

Does a package deal for generation of monoclonal antibody production exist?

A fixed price package for generation of a monoclonal antibody does not exist, since these types of services are individually designed in collaboration with our partner for immunization according to your exact needs.

Do you guarantee also the quality of the antibody / antiserum generated within your expression package "recombinant protein plus polyclonal antibody"?

Yes, we also guarantee the quality of an antiserum generated (polyclonal antibody). The final titer will be tested by ELISA.

Is double or triple labeling for guaranteed packages possible?

Double and triple labeling are possible. We offer the following labels, which can be combined in different combinations: 15N, 13C, D2O.

Customized Recombinant Protein Expression and Purification Services

What kind of analysis of the produced proteins do you offer?

We offer different analytical methods according to your needs. Always included is SDS-PAGE and determination of protein concentration. Very often we do Western blot analysis. If needed, we can determine the oligomeric state by analytical size exclusion chromatography (SEC) or native PAGE. Mass spectroscopic analysis is also offered on request to determine for example the modification of proteins.

Does trenzyme offer recombinant proteins off the shelf?

Yes, we offer various recombinant proteins off the shelf. Have a look at our continuously growing catalog.

Protein Expression Screening

Do you have experience with difficult-to-express proteins?

Yes, we have a lot of experience with difficult-to-express proteins. You can get more information by using our contact form on our website.

High-Yield Recombinant Protein Production

Is labeled high-yield protein production also available?

Yes, we have developed a protocol for high-yield production of labeled proteins in bioreactors at high-cell densities.

What is the typical yield and scale in your high-yield protein production?

The typical yield is not easy to predict, but can reach up to gram-quantities per liter of high-cell density fermentation runs (E.coli and Yeast). The scale can reach up to 8 l for bioreactors and 10 l for cell culture.

Antje Fuhrmann, PhD

Antje Fuhrmann, PhD

Application & Sales Manager

If your question has not been answered, please contact us and let us know your questions. Our scientific experts will reply shortly.

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