Associate Scientist II, Histology

Arrowhead Pharmaceuticals•San Diego, CA

4d•$70,000 - $78,000•Onsite

About The Position

Arrowhead Pharmaceuticals, Inc. is a commercial stage biopharmaceutical company focused on developing medicines that treat intractable diseases by silencing the genes that cause them. The Associate Scientist II is a key member of the Histotechnology team within the Toxicology Department. This team advances the company’s preclinical drug development by designing tissue-based study workflows and delivering high-quality histology data from animal studies. Working under the guidance of the Team Lead, the Associate Scientist II performs both routine and advanced histological methods with a high degree of independence, ensuring reproducible results and consistent section quality aligned with program needs. This role is onsite 5 days a week in San Diego.

Requirements

3-5 years in Histology field or B.S in Science with 1-2 years of Histological work
Familiarized with ELN, IHC, microtomy, basic anatomy

Nice To Haves

Degree from an accredited Histotechnology program, HT or HTL(ASCP) certification
Experience validating RNAscope/miRNAscope and multiplex IHC/IF across multiple tissues/species.
Familiarity with LIMS/ELN.
Familiarity with digital pathology and whole-slide imaging

Responsibilities

Plan and execute end-to-end histotechnology workflows for preclinical studies (tissue receipt, grossing/trimming, processing, embedding, microtomy, staining, imaging, and data handoff).
Perform paraffin microtomy and cryosectioning of small and large animal tissues at 5–7 µm with consistent quality across batches.
Conduct routine automated tissue processing and paraffin embedding across species; recognize processing issues (e.g., incomplete infiltration, tissue carryover, artifacts) and implement effective fixes.
Run routine and special stains on automated platforms (e.g., Leica Spectra and Ventana systems) with minimal supervision; complete instrument setup, QC, and maintenance logs.
Execute immunohistochemistry (IHC) and/or immunofluorescence (IF), including antigen retrieval, control selection, optimization, and troubleshooting; document conditions and outcomes.
Perform high-precision sectioning at optimal parameters to ensure maximum transcript preservation and morphological stability prior to in situ hybridization staining.
Assess tissue morphology and state; document findings accurately and recommend follow-up techniques or controls when appropriate.
Trim tissues from multiple species according to study protocols and nomenclature; ensure accurate cassette labeling and chain-of-custody tracking.
Support necropsy activities for small and large animals as requested, following biosafety, animal welfare, and PPE requirements.
Maintain meticulous records in lab notebooks/ELN and, when applicable, LIMS; draft or revise SOPs, work instructions, and checklists to improve reproducibility.
Collaborate closely with pathologists, toxicologists, and study directors to deliver large studies on time; communicate progress, risks, and mitigation plans proactively.
Uphold laboratory safety, housekeeping, equipment calibration/preventive maintenance, and reagent inventory management.
Provide schedule flexibility, including occasional weekend or overtime work, based on project timelines.