Senior Scientist – Protein Production

Main Responsibilities

This senior scientist will own recombinant protein production campaigns end-to-end, from construct design through expression, purification, and final quality control. The role spans multiple hosts and cell lines — bacterial, insect, mammalian, and yeast — and the full purification toolkit, with particular responsibility for the difficult targets that do not respond to standard approaches. As a senior member of the team, this scientist will mentor junior staff, author and maintain protocols and SOPs, own delivery timelines, and interface directly with clients on strategy, progress, and results.

Additional Responsibilities

• Design constructs and production strategies for new targets, including boundary selection, tag and fusion partner choice, codon optimization, and host selection.
• Execute and troubleshoot expression across bacterial, insect, mammalian, and yeast systems, including transient transfection, stable pool generation, and cell-free expression where appropriate.
• Run small-scale expression and condition screens, then scale up through shake flask, wave, and bioreactor formats, optimizing media, induction, and harvest conditions.
• Develop and execute purification strategies using affinity and IMAC, ion exchange, size exclusion, hydrophobic interaction, and other chromatographic methods, including tag removal, refolding, and complex reconstitution.
• Solubilize and purify membrane proteins, including detergent and amphiphile screening and reconstitution into nanodiscs or other supports.
• Perform and interpret QC by SDS-PAGE, analytical SEC, mass spectrometry, A280, and endotoxin testing, and deliver material to defined specifications for structural, biophysical, and functional studies.
• Own campaign timelines: plan resource needs, flag risk early, and keep client-facing milestones on schedule.
• Interface directly with clients: participate in kickoff and scientific update calls, present results, and support technical scoping and feasibility discussions for prospective projects.
• Mentor junior scientists and research associates, and author, review, and maintain protocols and SOPs.
• The candidate will be responsible for timely updates on project statuses, reporting to their supervisor informally and to Helix’s customers by formal report writing and oral presentations.

Required Qualifications

• Ph.D. in biochemistry, biophysics, molecular biology, protein engineering, or a related field with 4 or more years of relevant post-doctoral or industrial experience; OR a Master’s degree with 8–12 years of relevant industrial experience; OR a Bachelor’s degree with 12 or more years of relevant industrial experience.
• Demonstrated independent competency in recombinant protein expression across at least three of the following: E. coli, insect/baculovirus (Sf9, High Five), mammalian (HEK293, CHO), and yeast (Pichia, S. cerevisiae).
• Demonstrated competency in transient expression and stable pool generation, small-scale screening, and scale-up through shake flask and bioreactor or wave formats, including media and condition optimization.
• Demonstrated purification depth across affinity and IMAC, ion exchange, size exclusion, and hydrophobic interaction chromatography, including tag removal and AKTA-based method development.
• Hands-on experience with difficult targets: low-yield, unstable, aggregation-prone, multi-component, and/or membrane proteins, including refolding and detergent screening.
• Ability to generate and characterize milligram-to-gram quantities of high-quality protein reagents for downstream structural, biophysical, and functional studies.
• Experience with standard analytical and biophysical QC (SDS-PAGE, analytical SEC, mass spectrometry, A280, endotoxin) and with setting and defending release specifications.
• Demonstrated ability to mentor junior staff, author protocols and SOPs, and own delivery timelines.
• Strong written and oral communication skills, including direct client interaction.

Additional qualifications

• Prior industrial experience in a biotechnology or pharmaceutical company, or in a CRO or CDMO, is strongly preferred.
• Experience running multiple client-facing production campaigns in parallel to fixed timelines and specifications.
• Cell-free expression systems.
• Endotoxin-aware and low-endotoxin production workflows for cell-based and in vivo applications.
• Protein engineering and/or design approaches to improve expression, solubility, and stability.
• Antibody, Fab, VHH, and other biologics production and purification.
• Structural biology experience (X-ray crystallography or Cryo-EM), including preparing samples to structure-grade quality.
• Molecular biology workflows: molecular cloning, site-directed mutagenesis, vector design, and baculovirus generation.
• Experience with laboratory inventory, LIMS, or electronic lab notebook (ELN) systems, and with cell bank management.
• Excellent communication, interpersonal, and organizational skills.
• Fearless attitude to tackle longstanding complex problems.