Senior Research Associate (Cell Biology)

Senior Research Associate, Cell Biology (Assay Development)

Company Description

Gensaic combines AI-powered protein design with unbiased directed evolution to develop tissue-selective ligands for targeted intracellular therapeutic delivery. The company's portfolio advances therapies for metabolic and age-related diseases, with an initial focus on siRNA payloads. FORGE™, Gensaic's proprietary product engine, integrates phage libraries for unbiased protein evolution within a generative AI architecture to discover and optimize protein and peptide molecules with enhanced tissue selectivity and drug-like properties. Founded at MIT and based in Cambridge, Massachusetts, Gensaic's team of physicians, biologists, bioengineers, and machine learning scientists is advancing a singular objective: to enable selective delivery of any therapeutic payload to any tissue of interest. We are an early-stage startup and look for people who are passionate about science, community and doing good.

For more information, please visit gensaic.com.

Location

Cambridge, MA.

This is a fully onsite position. The role is primarily hands on lab bench work, and remote or hybrid work is not available.

Summary

We are seeking a hands-on, highly motivated Senior Research Associate to join our Assay Development team. You will own day-to-day mammalian cell culture (both immortalized lines and primary cells), build engineered and reporter cell models by transfection and transduction, and run the core cell-based and molecular readouts that drive our delivery programs: RT-qPCR for payload activity, ELISA and Western blot for protein quantification, and supporting flow cytometry and imaging. Your data will directly determine which ligands advance from in vitro screening into in vivo studies. You will work closely with scientists across protein engineering, synthetic biology, and screening teams to build and refine phage-based discovery platforms that drive the development of next-generation therapeutic and delivery technologies.

Key Responsibilities

• Maintain, differentiate, and bank immortalized and primary cells (e.g., hepatocytes, myotubes, adipocytes, neuronal or iPSC-derived) with rigorous aseptic technique
• Generate transient and stable cell models by plasmid, mRNA, and siRNA transfection and by lentiviral transduction, including virus production, selection, and clone isolation
• Run RT-qPCR end to end: RNA extraction from cells and tissues, cDNA synthesis, primer design, and ΔΔCt or standard-curve analysis
• Quantify proteins and biomarkers by ELISA and Western blot, and support flow cytometry readouts of delivery, viability, and cell-type markers
• Perform permeabilization and staining to detect delivered cargo that has reached the cytosol or nucleus
• Use high-resolution microscopy to visualize the spatial distribution of tagged proteins within target cells
• Execute dose-response and time-course studies of binding, uptake, and payload knockdown in 96/384-well format, and derive EC50/IC50
• Perform supporting molecular biology: PCR, plasmid prep, cloning, and sequence verification
• Work with the in vivo team to collect and flash-freeze tissue samples (CNS, liver, muscle) using RNase-free technique, and run downstream RNA and protein analysis
• Document in Benchling, maintain SOPs and inventory, and present data at team meetings

Qualifications & Experience

Required

• BS or MS in Cell Biology, Molecular Biology, Biochemistry, or a related field
• 4 years (BS) or 2 years (MS) of hands-on cell and molecular biology experience. Industry experience strongly preferred.
• Independent mammalian cell culture, including primary cells
• Transfection and viral transduction, including stable line generation
• RT-qPCR from RNA extraction through data analysis
• ELISA and Western blot
• Standard molecular biology (PCR, plasmid prep, cloning, nucleic acid QC) and comfort with Benchling, Prism, and Excel

Preferred

• Primary human or iPSC-derived models and differentiation protocols
• Oligonucleotide or nucleic acid delivery (siRNA, ASO, mRNA, LNP)
• Lentivirus or AAV production and titering; CRISPR knockout or knock-in lines
• DNA assembly and library construction (Gibson, Golden Gate) and site-directed mutagenesis
• Target-binding assays by BLI or SPR
• NGS library preparation from cell or tissue samples, and basic sequencing QC
• Flow cytometry panel design (FlowJo), quantitative image analysis, ddPCR, or plate automation
• Assay development and qualification, and mentoring of junior scientists

Personal Attributes

• Strong critical thinking and problem-solving skills; able to troubleshoot experiments and propose improvements
• Able to run multiple experiments in parallel and prioritize in a fast-moving, early-stage lab
• Meticulous attention to detail in experimental execution, documentation, and QC
• Collaborative and communicative team player eager to work across molecular, analytical, and computational interfaces
• Curious, adaptable, and driven to refine technologies that advance molecular discovery and therapeutic innovation

Why Join Us?

• Opportunity to work on cutting-edge machine learning applications to discover novel in vivo delivery technologies.
• Collaborative and inclusive research environment with opportunities for professional growth.
• Competitive compensation, benefits, and career development support.
• Make a meaningful impact on next-generation multi-functional RNA medicines.

If you are passionate about translational science and thrive in an interdisciplinary and fast-paced research setting, we encourage you to apply!

Culture at Gensaic

‘A place where everybody knows your name’

• Care about people and obsess about the science
• Celebrate diversity in everything
• Always communicate
• Show empathy and respect
• Deliver value
• Admit mistakes and shortcomings
• Sweat the details
• Laugh

Perks and Benefits

• Work with a talented and collaborative team
• Competitive compensation & equity package
• 401k, medical, dental, and vision insurance
• Continuing education and conference stipend
• Wellness stipend

We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, sex, gender identity, sexual orientation, age, marital status, veteran status, disability status, or any other characteristic protected by law.