Retro develops therapies for diseases driven by the biology of aging. We focus on cellular reprogramming and autophagy to rejuvenate cell and tissue function with the ultimate aim of adding 10 years to healthy human lifespan. We're building a mission-driven team of accomplished and kind individuals who embrace our startup culture of rapid iteration, transparency, and versatility. We are hiring a new member of the HSC team who will help bring G-banding and karyotyping in-house. You'll stand up this capability and enable our team to get faster, more cost-effective reads on the genomic stability of our cell products. You will be the primary internal owner of this capability and should be comfortable establishing and validating the workflow with limited day-to-day cytogenetics supervision. Your primary focus will be establishing and running the cytogenetics assay, but you'll also help maintain our iPSC cultures — the starting material the assay depends on.  \n About you: You're a careful, hands-on technologist who takes pride in high-quality chromosome preparations and confident karyotype calls. You are comfortable bringing an established cytogenetics workflow into a new laboratory environment—setting up the process, confirming that it performs consistently, documenting it clearly, and troubleshooting issues as they arise. You're at home at the microscope and equally happy in a tissue-culture hood keeping iPSC lines healthy. You're collaborative, easy-going, proactive in how you communicate, and flexible about scheduling when the culture rotation calls for it. What you'll do in this role: * Transfer in, implement, and document an established G-banding and karyotyping workflow in-house for HSC program cell products. * Execute the full cytogenetics workflow (initially in research/PD and then in our GMP suite): metaphase arrest, cell harvest, hypotonic treatment, slide preparation, fixation, Giemsa staining, metaphase imaging, and software-assisted karyotype analysis. * Compare initial in-house results against historical data and document appropriate operating and quality-control criteria. * Analyze metaphase spreads to identify numerical and structural chromosomal abnormalities, and document findings clearly. * Support genomic-stability assessment of human primary cells  * Culture, passage, expand, bank, and prepare iPSC samples in preparation for karyotyping  * Track clone-level genomic stability, passage number, culture conditions, and QC status across lines. * Coordinate with CROs shipments of samples for genomic instability analysis * Maintain organized records, sample tracking, and imaging files, and develop SOPs for the workflows you build. You might thrive in this role if you: * Have several years of hands-on G-banding and karyotype analysis experience, with demonstrated ability to make independent chromosome assessments and troubleshoot chromosome preparation and image quality. * Have experience with imaging software such as MetaSystems / Ikaros or Cytovision. * Have hands-on mammalian cell culture experience with strong sterile technique. * Are comfortable with high-magnification microscopy. * Are highly organized and able to run multiple clone/sample workflows in parallel. * Are available for weekend work as part of a team rotation. Bonus if you: * Have experience standing up or validating a new assay in-house. * Hold current CG(ASCP) certification in cytogenetics. * Hold a Bachelor's or Master's degree in cell biology, molecular biology, cytogenetics, genetics, stem cell biology, biomedical sciences, or a related field. * Have hands-on experience maintaining iPSC cultures. \n $115,000 - $150,000 a year At Retro, we don't use titles. New hires join as a "Member of X Team." The expectations for this role are generally aligned to the level of Cytogenetics Technologist. Total compensation also includes generous equity and benefits including: * Medical, dental, and vision insurance for you and your family * 401(k) plan with 4% matching * Unlimited time off and 10 company holidays per year * Annual learning & development stipend * Free lunch and snacks \n We take pride in cultivating an environment that fosters collaboration, open communication, and authenticity. We are an equal opportunity employer; we do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.