Job Description

About Until
Until is a moonshot company building a “pause button” for biology. Our near-term focus is organ-scale reversible cryopreservation: preserving donated organs at subzero temperatures without ice formation, then rewarming them uniformly for transplant. By solving this challenge, we are laying the foundation for whole-body reversible cryopreservation, giving patients a bridge to future cures.
To achieve our goal, we are assembling an interdisciplinary team to develop perfusion systems, cryoprotectant formulations, and vitrification and rewarming hardware.We envision a future where no transplantable organ is lost to logistics, and no terminal diagnosis is final because patients can safely wait for future medicine to arrive. 
About the Role
We are seeking a highly skilled ECMO Perfusionist to support preclinical large-animal studies involving extracorporeal membrane oxygenation (ECMO) and cardiopulmonary bypass systems. Our studies involve transitioning animals from normothermic blood perfusion to hypothermic, non-blood perfusion with cryoprotectant solutions, followed by controlled rewarming and reperfusion with blood. Each phase presents distinct physiological and biochemical challenges that can impact organ viability and whole-body recovery.
This position extends beyond traditional ECMO management and requires deep physiological insight, strong troubleshooting skills, and protocol optimization experience. The perfusionist will be responsible for identifying key failure points, diagnosing mechanisms of injury, and proposing meaningful protocol modifications to improve recovery outcomes.

Key Responsibilities

• Oversee and manage whole-body perfusion procedures, systematically identifying critical procedural variables that can be optimized to improve overall animal health and recovery outcomes.
• Evaluate and diagnose physiological injury resulting from cryoprotectant exposure and temperature transitions during cryopreservation, including organ-specific and systemic effects.
• Develop and recommend data-driven modifications to cryoprotectant formulations, perfusion parameters, and cryopreservation protocols to enhance safety, reduce tissue damage, and improve whole-body resuscitation post cryopreservation.

Qualifications

• 3+ years ECMO perfusion experience 
• Demonstrated a passion for rapid problem solving and success working through novel hard problems
• Desire to work in a laboratory setting