Stable Cell Line Generation

Case 1: Tag-Free Vaccine Protein

During the generation of stable cell lines, cells are selected and screened to identify clones that stably express the protein of interest at desired levels. This case study illustrates the successful generation of a tag-free vaccine protein. Through a rigorous process, cells were engineered to express the target protein without the addition of any tags or fusion partners, ensuring the purity and integrity of the vaccine candidate.

The images below from our single cell image system confirm the monoclonality of the clones. This step ensures that each clone originates from a single progenitor cell, eliminating genetic heterogeneity within the population and guaranteeing uniform expression of the vaccine protein. The final yield of the obtained clone A was 2.31 g/L.

The stability of clone A was also tested by assessing the doubling time of the cells, cell density and yield. The cells were subcultured in CD04 medium containing 25 uM MSX, and the chart below shows the doubling time of 22 ± 1 hour (average: 22.6h).

Cells from passages 3, 8, 13, 18, and 23 were collected to assess cell density. Results indicated a consistent level of cell growth.

Cells from the same passages 3, 8, 13, 18, and 23 were also assessed for yield. The results indicated that over 90% productivity titer was retained for over 22 passages.

By systematically assessing the stability of clone A through comprehensive growth kinetics and protein yield analyses, this case study provides valuable insights into the suitability and robustness of the generated stable cell line for biopharmaceutical applications.

Case 2: Anti-PD1

In this case study, the objective was to generate stable cell lines capable of producing an anti-PD1 therapeutic. The process involved the selection and assessment of three single clones, followed by purification and characterization.

The productivity of the selected clones was assessed using three different commercial media formulations. The results of this assessment provided insights into the optimal growth conditions for each clone.

After one step of affinity purification, both reducing and non-reducing CE-SDS analyses were performed to evaluate the purity of the three clones. The results indicated a purity of >97%.

CEX-HPLC analyses were then conducted to assess the charge of the three clones. The results indicated a similar main component percentage compared to the positive control for the first two clones. Notably, the first clone (B414203-N42-6-N1) exhibited the most similar basic component percentage, indicating its potential suitability for further development.

Overall, the findings from this case study highlight the successful generation and characterization of anti-PD1 stable cell lines.

We have currently sublicensed the CHOK1BN cell line to multiple clients, and the project statuses of some of these clients are shown below: