Cell Line Development Specialist (female/male)

Key responsibilities

• Perform core CLD related activities including transfection, selection, and single cell cloning (using platforms like limiting dilution, FACS, single cell printer, cytomine, etc.) for mammalian cell lines (typically CHO).
• Conduct fed-batch evaluations in shake flasks and automated systems (e.g., Ambr15) to assess clone productivity and stability.
• Participate in the design and construction of plasmids encoding the gene of interest (GOI) using bacterial expression systems.
• Execute experimental workflows to generate stable, high-producing recombinant cell lines for monoclonal antibodies, ADCs, fusion protein programs.
• Maintain, expand, and bank mammalian cell lines under aseptic, GMP-aligned laboratory conditions.
• Develop and optimize cell culture processes, selection strategies, and cell line engineering protocols.
• Characterize clones using productivity assays (flow cytometry, Octet, qPCR), cell growth/metabolic profiling, and stability assessments.
• Maintain accurate documentation including electronic lab notebooks (ELN), and data summaries.
• Contribute to technology transfers to upstream process development, manufacturing, or external CDMOs.
• Participate in troubleshooting, method optimization, and lab process improvement initiatives.
• Ensure compliance with EHS, biosafety, and quality standards across all lab activities.

Requirements

• Master's degree preferably in Biotechnology, cell biology, molecular biology, biopharmaceutical or related.
• Hands-on experience with CHO or other mammalian cell culture with proven knowledge of biosimilarity (up to 4 years of industry experience).
• Demonstrated ability to guide and supervise less experienced colleagues.
• Working proficiency in written and spoken English.
• Availability to work five days a week, eight hours a day.
• Proficient in MS Office (Excel, PowerPoint, Word); MS Project is a plus.
• Effective communication skills and openness to new challenges and collaboration.
• Strong organizational skills with the ability to prioritize and multitask.
• Commitment to accuracy, timeliness, and continuous learning.

What we offer

• Employment at a leading company in Poland’s biotechnology sector.
• Engaging and meaningful professional challenges.
• Competitive salary with annual and special occasion bonuses.
• Attractive benefits package, including:
  • Private medical care.
  • Life insurance.
  • Employee Pension Program (PPE) and Employee Retirement Support (PWE).
  • One additional paid day off per year.
  • Flex Benefits budget (choose from options like MultiSport or Pluxee lunch card).
  • Financial support for skill development.
  • Weekly fruit and vegetable days.
  • Access to psychological support.

Important: Please ensure that your application is submitted in English.

At Rezon Bio, we believe in diversity and equality. Our recruitment process is conducted in a fully transparent manner and with respect for non-discrimination principles – regardless of gender, age, orientation, gender identity, or other individual characteristics. We encourage all individuals who meet the requirements to apply, including women, men, and non-binary persons. What matters most to us is your experience, skills, and passion for achieving goals together!