Meet A51 and the team shaping programmable biology

A51 is a biotech company engineering RNA to reprogram cellular states. We are shifting drug discovery toward drug engineering, where RNA becomes the programmable layer of biology. By combining microfluidic biocomputation with cutting-edge computational design, we program RNA molecules tailored to tackle the most complex diseases. Backed by a top-tier Silicon Valley VC and based at the most iconic French incubator Agoranov in the heart of Paris, we operate at the frontier of innovation.

Our mission is to make biology engineerable by rapidly designing functional RNAs that modulate cell behavior. Beyond treating disease, this opens the door to regenerative medicine and real-time cellular reprogramming. We’re a global, interdisciplinary team spanning wet lab, computation, and engineering, working on some of the hardest problems in biotech. If you want to help turn science fiction into reality, A51 is the place to do it.

What you’ll do

As our first Microfluidic Engineer, you’ll own the development and execution of microfluidic experiments for high-throughput RNA screening and cellular phenotyping. You will design custom chips, develop biocomputation workflows in droplets, and integrate them with our imaging and computational platforms. This role combines design, fabrication, hands-on experimentation, and strategic problem-solving. You’ll work closely with biologists, computational scientists, and external partners to build a system that is capable of driving real-time RNA evolution at the cellular level. This is a builder’s role offering the opportunity to co-design frontier biology and build A51 together.

Responsibilities

• Design and prototype microfluidic chips tailored for biological computation and screening workflows
• Perform real-time assays in droplets or custom chambers, including fluorescent imaging and cellular readouts
• Operate and maintain high-end imaging systems (e.g., confocal, widefield, or spinning disk microscopy)
• Build and troubleshoot microfluidic experimental setups, including flow control, emulsion generation, and custom interfaces
• Coordinate with biologists and software engineers to ensure smooth integration across disciplines
• Interface with external contractors, CROs, and fabrication partners to manage outsourced production
• Maintain lab instrumentation, ensure system reproducibility, and contribute to improving experimental throughput

About you

• You’re comfortable in fast-moving environments where nothing is fully defined and everything constantly changes
• You enjoy working with interdisciplinary teams and learning new tools
• You thrive at the bench, take initiative, and enjoy troubleshooting biological problems
• You think critically, communicate clearly, and value reproducibility

Required qualifications

• Jack-of-all trades - everything changes - all the time
• MSc or PhD in Bioengineering, Applied Physics, Microfluidics, or related fields
• Hands-on experience designing and executing microfluidic workflows in biology
• Ease with different microfluidic designs (droplets, wells) and cell handling in chips (trapping, encapsulation, co-flow, etc.)
• Experience working with live cells in microfluidic formats
• Strong troubleshooting skills; ability to iterate quickly and independently
• Comfortable with imaging-based assays (fluorescent or label-free); experience with confocal microscopy is a plus
• Fluent in French or English (ideally both)

Nice to have

• Prior experience in a biotech startup or high-velocity R&D environment Familiarity with chip-design tools (e.g., AutoCAD, SolidWorks)
• Experience working with CROs or external manufacturers to coordinate device fabrication
• Integration of microfluidic data with computational approaches

What we offer

• A fast-moving, ambitious team with strong mentorship, intellectual ownership, and global mission
• A chance to build the microfluidic core of a frontier biotech company
• Competitive salary package (based on seniority)
• Health/retirement/benefits coverage
• Equity depending on contract type and level of seniority

Questions? contact@a51tx.com

Application: fill out the form below + send CV to contact@a51tx.com