Stable cell line development services are tailored to our partner`s research. Recombinant cell lines established through viral transduction or stable transfection with conventional or transposon-based DNA vectors providing quick turnover polyclonal cell lines or fully validated monoclonal cell lines with desired characteristics.

Stable cell lines are confirmed for target expression via immuno-based or PCR-based analysis methods (FACS, WB, IF, RT-PCR) and further validated in cell-based assays to confirm the functional expression of the target protein or reporter gene. Multicolor flow cytometry, non-invasive live cell imaging or high-resolution fluorescence microscopy further enable deep characterization of stable cell lines for protein localization, cell growth behavior or other phenotypic parameters.

Cell line development capabilities include:

• Over-expression or knock-down strategies via viral or transposon-based gene delivery
• Custom vector design with highly flexible promoter and resistance markers choice
• Constitutive and inducible expression of target or reporter genes
• Polycistronic or independent co-expression of auxiliary factors or protein complex subunits
• Generation of stable pools or single clones with broad range of target expression levels
• Target expression analysis and functional or phenotypic validation in cell-based assays

Membranes are produced in either crude or highest quality, by gentle cell disruption methods. Customised aliquots are prepared to fit individual Partners projects’ demands. Membrane is confirmed via Western blot analysis, and as needed demonstrated by functional ligand binding.

• Cell membrane preparation from transiently expressed cells and stable cell lines
• Large scale preparation of up to 5 billion cells in a single or multiple batches
• Gentle and highly efficient cell disruption by nitrogen decompression using a different state-of-the-art cell disruptors (e.g., PARR-bomb^® or micro-fluidizer)
• Enrichment of membranes by differential ultracentrifugation
• Quality control, typically by Western blot and optional Ligand binding assay

Validation of membranes by radioligand binding assays:

• Filter binding or Scintillation Proximity Assay (SPA)
• Saturation binding (Bmax, K_d), Kinetic binding (K_off), competitive binding (EC₅₀)
• Screening of agonists, antagonists and allosteric modulators

Our Cellular Sciences team has a long expertise in producing assay ready frozen cells (ARFs):

• Bulk-production – up to 10 billion (1E10) cells in a batch
• Produced from adherent or suspension cells, permanent cell lines, primary cells, or transiently transfected cells
• Fast harvest, automated filling and controlled rate freezing

Advantages of ARFs:

• High quality ready-to-use cells available on stock
• Simplifies assay workflows by using cells like a reagent
• Saves time and work on maintenance cell culture

• Stable quality without passage effects
• High reproducibility of data even after months
• Re-order at same quality

Ideal for example for the following applications:

• High throughput (HTS campaigns)
• Long term demand (QC with bioassay)
• Extensive parallel culture (tumor line profiling)

Transient bulk transfection are available to overcome limitations with targets which are not stably expressed in mammalian cells or to enable fast access to target-expressing cell lines.

A variety of gene delivery technologies including large scale lipofection, electroporation and viral transduction to achieve transient expression of toxic or complex targets. The transient transfection approach allows for instant access to cell-based reagent in bulk quantities with high target expression levels.

Scalable transient transfection by electroporation using MAXCYTE^® STX technology:

• Highly efficient transfection of up to 10 billion cells in a single batch
• Adjustable expression levels for functional cell-based assays or high yield protein expression
• Downstream processing of transfected cells to assay ready frozen cells, membrane preparations or purified proteins