Cell Line Development


i.e. GMP-compatible CHO cell line development​

IcoCell platform is a well characterized proprietary host cell line platform to efficiently generate GMP-compliant stable CHO cell lines for production of recombinant proteins.

General workflow overview using the IcoCell platform: 

A cell line development project is divided into three main stages:

1.     DNA expression vector construction and preparation

Cell line development project starts with the design, construction and preparation of DNA expression vectors. The proprietary DNA expression vector is used for cell line development that is specifically designed to Icosagen’s CHO cells. The expression cassettes are optimized using carefully selected regulatory elements and secretion signals for enhanced secretion, as well as additional unique elements promoting the integration of transgene into transcriptionally active region of CHO genome.


2. Transfection into CHO cells and selection of high-producing minipools

The linearized DNA vector is transfected into parental CHO cell line, and after the secreted expression of desired recombinant protein is confirmed, the selection of hundreds of minipools is initiated. Up to 15 of the best minipools are cryopreserved based on the fed-batch productivity determined.

3. Monoclonal cell line development

The lead cell minipools are subjected to single cell cloning procedure with VIPS™ Solentim that couples a single-cell printing method with high resolution imaging system to provide assurance of clonal derivation.

Up to 10 of the best clones are selected and cryopreserved based on the production titers and product quality attributes.

  Stability Study

The cell line stability is a crucial component of production for cell bank characterization demonstrating the cell line's suitability for use in a manufacturing process. During stability testing, the expression stability and product quality attributes are evaluated over 60 generations, that is the typical length over which the stability of a CHO manufacturing cell line is assessed based on the manufacturing window.

Up to 10 of the best performing cell clones are thawed from cryopreservation, and passaged until the generations of 20 and 60 are reached. Thereafter, the cell cultures are subjected to 14-day fed-batch production in order to evaluate expression stability by using ELISA or BLI method (Octet). Additionally, cell growth rate and maximum viable cell density is analyzed together with product quality attributes such as glycosylation profile (HILIC), charge variants (IEF), aggregate levels (analytical SEC), protein sequence heterogeneity (mass spectrometry) are assessed over the three different population doublings (PD).

The final cell clone is chosen based on the product titer and product quality attributes. 40 vial RCB is generated for the best performing monoclonal CHO cell line that is released after biosafety tests.


Main advantages of our IcoCell GMP-compliant Cell Line Development Platform

1.     Gene(s) of interest is:

  • integrated into the transcriptionally active genomic regions and actively transcribed (high titers);
  • not silenced during the periods of selection and production (stable expression).

2.     Fast timelines due to the single cell cloning by VIPS™ Solentim that couples single-cell printing method with high resolution imaging system.

3.     VIPS™ Solentim “double lock” method is used to assure 99.9% monoclonality.

4.     Minipool selection approach can be started in parallel with the final selection of antibody variants (parallel processes save time)

5.     GMP - compatible documentation is provided.

6.     Pure fee-for-service, no clinical milestones, no royalties.