Scientist

The fight against cancer needs new, big, bold ideas. At Siren, we’ve got one: Universal AAV Immuno-Gene Therapy. We are combining two transformative therapeutic technologies — adeno-associated virus (AAV) gene therapy and cytokine immunotherapy — into a single, reimagined modality designed to destroy tumor cells and elicit anti-tumor immunity.

We’re sounding the alarm against cancer!

Position Description:

We’re looking for a Scientist 1 to be the hands-on engine of our translational research. Reporting to the Director of Translational Research, you will own our small in-house lab and drive the experimental work that moves our programs forward, while also handling the non-lab work around it: managing contract research organizations (CROs), writing study reports, compiling data for presentations and publications, and coordinating externally run assays. On any given project you may lead the science from concept to completion, or be handed a discrete task and asked to execute it well. Both modes are core to the job.

This is a unique role, so we want to set expectations clearly:

• Translational Research covers all nonclinical work at Siren: early R&D, proof-of-concept pharmacology, IND-enabling data packages, clinical development strategy, and assay development for animal and human samples.
• The split between onsite lab work and remote computer work is neither fixed nor predictable. Some months you may be in our San Francisco lab nearly every day; other months there will be no lab work at all. Your schedule will need to be flexible.
• We are located at MBC BioLabs, which provides excellent operational support and a community of peers. You will be Siren’s only bench employee and the point person for everything that happens there — running assays, keeping equipment functional, and keeping the space safe and clean.
• You will not, however, be isolated. Our small San Francisco team (CEO, Director of Corporate Strategy, and Director of Translational Research) moves fluidly between remote and in-office work and gathers in the office twice a month, and you will collaborate regularly across translational, clinical, CMC, and corporate areas.
• Your scope is deliberately broad: like everyone at Siren, no task is outside your remit. The role requires owning the unglamorous operational work alongside the breakthrough science, and will suit someone energized by variety and by a direct line of sight into how a clinical-stage program is run.

Responsibilities

Lab responsibilities are expected from day one. Non-lab responsibilities can be learned along the way, but you should already show strong aptitude and be able to ramp quickly with minimal guidance.

• Perform mammalian cell culture, including primary cells, cell line expansion, and working cell bank generation.
• Run Siren’s qualified cell-based and ELISA-based assays in-house with tight accuracy and precision, after training, with minimal oversight.
• Process and analyze in vivo study samples, including animal tissues and biofluids, to inform biodistribution, safety, and pharmacology. Required assay experience: ELISA, qPCR, and basic (≤5 color) flow cytometry.
• Identify gaps in our assay repertoire and propose analytical solutions. Develop and qualify fit-for-purpose in vitro and ex vivo assays (e.g., ELISA, Luminex/MSD, qRT-PCR, RNAscope, immunohistochemistry, dPCR) and document them as SOPs. Oversee method transfer to collaborators as needed.
• Own project-based lab initiatives end to end — e.g., in vitro screening of candidate AAV capsids or promoters, or transcriptomic profiling of treatment response.
• Execute one-off experiments on request (e.g., “run an ELISA on this AAV lot”).
• Serve as sole point person for lab operations: sample receipt, storage, inventory, and aliquoting; shipping to and receiving from external collaborators; logging work in Benchling; and maintaining lab safety, cleanliness, equipment, and consumables.
• Oversee the contract bidding process for new collaborations: set project scope, develop the design into a request for proposal, conduct vendor outreach and obtain confidentiality and transfer agreements, then compare bids and recommend vendors and CROs.
• Oversee assay development with collaborators from early method development through formal validation, learning unfamiliar assay formats on demand. Serve as point person for in vitro assay development, interpreting ICH and FDA guidance to set phase-appropriate qualification metrics.
• Help manage collaborators running our in vivo pharmacology, biodistribution, and toxicology studies: study design (with guidance), protocol finalization, and sourcing materials and safety documentation for dosing.
• Support the interface between translational research and clinical operations, including managing externally run clinical assays (contracts, shipping, logistics).
• Communicate with collaborators throughout our studies, analyze the resulting data, and summarize progress in presentations or project management software.
• Help the Director of Translational Research develop timeline and budget estimates.
• Write study reports for in-house and collaborator work (co-authoring with external partners where relevant; these may support regulatory filings), and author and edit clinical documents related to patient sample testing.
• With guidance, prepare corporate decks, publications, conference posters, and regulatory filings. Independently build figures in GraphPad Prism, and learn new analytical or image-processing tools (e.g., R, Adobe Illustrator, ImageJ, AI tools) as needed.
• Represent Siren at conferences (e.g., as a poster presenter).

A Across the role, you will

• Perform all activities in compliance with applicable regulations, company policies, and guidelines, plus other duties reasonably related to the role.

Qualifications:

Required for lab work (non-negotiable, day one):

• BS or MS in molecular biology, cell biology, biochemistry, immunology, or a related field (PhD also welcome). Prior industry experience is required.
• Demonstrated, hands-on expertise running ELISA, qPCR, mammalian cell culture, and processing and analyzing samples from animal studies.
• Rigor with assay controls, quality control, documentation, and reproducibility.
• Proficiency with GraphPad Prism and with an electronic lab notebook (Benchling preferred).

Required for non-lab work (teachable, but you should already be strong here):

• Strong scientific and technical writing; able to draft clear study reports.
• Aptitude for vendor and CRO management, including quotes, contracts, and logistics.
• Comfort building publication-, presentation-, and regulatory-grade figures.
• Able to learn new methods, domains, and software quickly with minimal assistance.

Required — ways of working:

• Live within commuting distance of the lab and be able to come onsite with 24h notice during working hours.
• Comfortable with a schedule that shifts unpredictably between full onsite lab weeks and fully remote weeks.
• Self-directed and reliable as the only person in the lab.
• Self-starter and team player who thrives in an early-stage environment.
• You take pride in running an assay to a standard on which someone would base a clinical trial design.
• You are motivated by the opportunity to build something meaningful for patients.
• You work effectively with people of diverse backgrounds, experiences, and perspectives.
• Clinical-stage Series A start-up backed by Founders Fund, Lux Capital, and Innovation Endeavors
• University of California, San Francisco (UCSF) spin-out from the Paulk lab
• California Institute of Regenerative Medicine (CIRM) TRAN1 and CLIN2 grant awardee
• 2025 Start Up of the Year (Advanced Therapies Awards); Pepperdine 2025 Most Fundable Companies; 2024 Therapeutics Innovation of the Year (Biotech Breakthrough Award)

Physical Demands of the Work Environment

• Full-time, with a variable split between onsite lab work in our shared MBC BioLabs incubator and remote, computer-based work.
• Lab work involves routine handling of biological samples, including AAV vectors and animal- and human-derived tissues and biofluids, requiring PPE and adherence to applicable biosafety procedures.
• The role requires extended periods standing at the bench, repetitive pipetting, and use of standard lab equipment including centrifuges, biosafety cabinets, and ultra-low (-80°C) and cryogenic storage. Occasional lifting of up to 25 pounds may be required.
• Remote work involves extended computer use, video and phone meetings, and data review.
• As the sole lab occupant, the employee will at times work independently. Siren maintains an Injury and Illness Prevention Program and provides safety training, and will provide reasonable accommodations as required by law.

Compensation and Benefits

• Competitive salary ($125,000-$150,000), commensurate with experience
• Equity compensation through Siren’s stock option plan
• Platinum health, dental, and vision benefits

Additional Employment Information

This is a full-time exempt position combining onsite laboratory and remote work on a variable schedule; the employee must be able to work onsite during normal business hours on short notice. Candidates must be authorized to work in the United States.

Siren Biotechnology is an equal opportunity employer committed to an inclusive workplace, and does not discriminate on the basis of any characteristic protected by applicable federal, state, or local law. Reasonable accommodations are available for qualified applicants and employees with disabilities and for sincerely held religious beliefs, practices, or observances, as required by law.

Pursuant to the San Francisco Fair Chance Ordinance, we will consider for employment qualified applicants with arrest and conviction records.

Siren does not seek or rely on salary history in determining whether to hire an applicant or what compensation to offer.