Principal/Senior Scientist, mRNA engineering

NewLimit; South San Francisco (CA); On-site; USD 160,000 - 185,000; Full time

Benefits offered by this job

Health, dental, and vision insurance

401(k) with company match

Paid parental leave

20 days PTO/year

Meals and snacks on-site

Job summary

NewLimit in South San Francisco is seeking a Senior Scientist to lead mRNA production efforts. This hands-on laboratory role requires scaling mRNA synthesis, purification, and characterization, ensuring the highest quality standards. Ideal candidates will have a PhD in a relevant field or extensive industry experience, hands-on expertise with nucleic acid production, and proficiency in quality control assays. The position offers a salary range of $160,000 to $185,000 and generous benefits including health insurance and 401(k) match.

Qualifications

• PhD or equivalent industry experience (5+ years).
• Deep hands-on experience with scaling nucleic acid production.
• Strong experience in drafting technical reports and protocols.

Responsibilities

• Execute and scale end-to-end mRNA production.
• Implement quality control assays and author SOPs.
• Train and manage team members on production workflows.

Skills

Hands-on experience with IVT

Proficiency with TFF

Technical report drafting

mRNA QC assay interpretation

Education

PhD in molecular biology or related field

Tools

Chromatography systems

Job description

NewLimit is a biotechnology company working to radically extend human healthspan. We’re developing medicines to treat age-related diseases by reprogramming the epigenome, a new therapeutic mechanism to restore regenerative potential in aged and diseased cells. We leverage functional genomics, pooled perturbation screening, and machine learning models to unravel the biology of epigenetic aging and disease using experiments of unprecedented scale.

Position

NewLimit is seeking a Senior Scientist to drive our mRNA production and engineering efforts. This is a hands‑on, lab‑based role focused on the synthesis, purification, and characterization of mRNA at large scales and high purities. You will serve as the technical lead for our production workflow, bridging the gap between molecular design and high‑quality material generation for in vivo and in vitro studies.

What you'll do

As a member of our team, you will:

• Execute and scale end-to-end mRNA production, including template preparation, in vitro transcription (IVT), and purification (TFF, chromatography).
• Implement rigorous quality control assays, including direct RNA sequencing, fragment analysis, dsRNA quantitation, and residual contaminant analysis.
• Author and maintain detailed SOPs and batch records, ensuring all production runs meet GLP standards.
• Independently design and execute experiments to improve mRNA sequence potency, specificity, and manufacturing performance.
• Train, manage, and mentor other team members on mRNA optimization and production workflows.

Requirements

• PhD in molecular biology, biochemistry, cell biology, or a related field or equivalent industry experience (5+ years).
• Deep hands‑on experience with IVT and the specific challenges of scaling nucleic acid production.
• Proficiency with TFF and chromatography systems for the purification of large scale RNA batches.
• Ability to perform and interpret mRNA QC assays and troubleshoot mRNA production challenges.
• Strong experience in drafting technical reports and standardized protocols.

Nice to have

• Familiarity with Python or R for sequence analysis and secondary structure prediction.
• Understanding of how mRNA quality attributes impact Lipid Nanoparticle (LNP) formulation and delivery.
• Experience with complex plasmid design and bacterial scale‑up for DNA template generation.
• Experience managing external contract manufacturing organizations (CMOs)

NewLimit offers generous benefits to ensure our team can focus on our mission:

• Health, dental, and vision insurance
• 401(k) with company match
• Paid parental leave
• Industry-leading paid time off (PTO) — 20 days/year for all employees + holidays
• Meals and snacks on‑site

Salary Range: $160,000 to $185,000. Compensation for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. NewLimit offers a competitive benefits package, which includes a 401k, healthcare coverage, and 20 days of PTO. Learn more at: https://www.newlimit.com/careers *This compensation and benefits information is based on Company's good faith estimate as of the date of publication and may be modified in the future.