Airtree is advertising this role on behalf of one of our portfolio companies, who are currently in stealth mode.

We exist to drastically increase access to advanced medicines. We are looking for experience bioreactor operators to support upstream development.

We’re hiring an experienced operator to assemble, sterilise and run a fleet of up to 16 benchtop bioreactors - twelve 300 mL vessels and four 3 L vessels - safely, aseptically and on schedule.

Why this role exists

This is an execution-first role, not an experimental-design role. Our scientists define the question, set the run parameters and interpret the data; you make those plans happen reliably. The job is to make a large reactor fleet feel routine through flawless preparation, clean technique, repeatable operation and complete records — and to solve normal equipment and controls problems without pulling a senior scientist away from their work.

The Role

• Operating the full 16-reactor fleet: twelve 300 mL and four 3 L mammalian-cell-culture bioreactors, often in parallel and on shared run schedules.
• Assembling vessels, tubing, probes, spargers and single-use components; leak-checking assemblies and staging everything required for each run.
• Cleaning, sterilising or autoclaving, reassembling and turning vessels around to a defined daily rhythm so the next run starts on time.
• Executing approved run plans exactly: inoculation, media and feed additions, set-point changes, sampling, harvest and sample hand-off.
• Calibrating and maintaining pH, dissolved oxygen and temperature probes, and checking gas, agitation, pump and alarm functions before use.
• Troubleshooting controls and cascade behaviour independently — including DO, gas-mix, agitation, pump and sensor issues — and knowing when a problem genuinely needs escalation.
• Protecting the sterile boundary throughout every run; recognising contamination early and leading the immediate isolation, clean-down and recovery response.
• Processing and labelling samples consistently, maintaining chain of custody and ensuring scientists can trust the resulting data.
• Completing electronic records, run logs, deviations and equipment checks in real time, and keeping consumables and work areas inspection-ready.

Requirements

Essential

• At least three years of hands-on industry experience operating mammalian cell-culture bioreactors. Academic-only experience is not sufficient for this role.
• Demonstrated experience assembling, sterilising, inoculating, sampling, feeding, harvesting and turning around benchtop bioreactors.
• Working knowledge of bioreactor controls and cascades. You can diagnose common probe, gas, agitation, pump and alarm problems without waiting for a scientist to fix them.
• Excellent aseptic technique and a practical understanding of contamination prevention, detection and response.
• Strong operational discipline: you prepare ahead, follow approved procedures, document as you go and raise exceptions early.
• Able to work a consistent full-time schedule that includes at least one weekend day — for example Sunday to Thursday or Tuesday to Saturday.
• The right to work in Australia and the ability to work on site in Alexandria, Sydney.

Nice to have

• Experience with parallel bioreactor systems or multi-vessel operations at approximately 250 mL to 5 L scale.
• CHO cell culture, antibody production or other industrial mammalian-cell-culture experience.
• Experience in a GMP, GLP or similarly controlled environment, including electronic batch records, ELNs or LIMS.
• Hands-on equipment maintenance or process-control experience beyond routine operation.

How We Work

Small team, fast cycles, flat. This is an on-site role in Alexandria, Sydney, with a consistent schedule that includes four weekdays and one weekend day. You will work from run plans designed by our scientists and alongside the people responsible for lab operations, media preparation and analytics. We value high standards, direct communication and people who fix the system rather than work around the same problem twice.