Staff Scientist

Craif is a rapidly growing Japanese biotech startup with a commercially successful diagnostics business, generating over $1,400,000 in monthly revenue through partnerships with more than 2000 medical institutions in Japan. Leveraging our cutting-edge urine-based miRNA assay platform for early cancer detection, we are now expanding our operations to the United States.

We are seeking a dedicated and innovative Staff Scientist who is passionate about building both technologies and laboratory infrastructure from the ground up as we establish a new U.S. based research facility.

The Staff Scientist will play a key role in developing, optimizing, and validating miRNA-based assays using liquid samples, with a strong focus on urine. This role involves executing complex wet‑lab experiments, establishing laboratory capabilities, and collaborating closely with scientific teams in both the U.S. and Japan. This is a full‑time, onsite position located in San Diego, CA.

• Lead and perform wet‑lab experiments involving miRNA assays from urine samples.
• Develop, optimize, and validate assay protocols for early cancer detection workflows.
• Design experimental plans, execute assays with high precision, and interpret results with scientific rigor.
• Troubleshoot experimental challenges, identify root causes, and propose data‑driven solutions.
• Help establish and maintain the laboratory, including equipment setup, calibration, and daily maintenance.
• Manage reagent inventory to ensure smooth laboratory operations.
• Document protocols, results, and observations accurately and consistently.

• A degree in Biological Sciences or a related field, and one of the following:
• 8+ years of relevant industry experience with a Bachelor’s degree
• 5+ years of relevant industry experience with a Master’s degree
• 2+ years of relevant industry experience with a PhD.
• 3+ years of hands‑on experience with next‑generation sequencing (NGS), preferably using Illumina platforms.
• Excellent verbal and written communication skills.
• Strong ownership mindset and motivation to advance diagnostic assay development.
• Ability to thrive in a fast‑paced, rapidly evolving startup environment.

• Proficiency in RNA handling and NGS library preparation.
• Experience working in a startup environment.
• Experience with liquid biopsy workflows.

• Hands‑on and proactive
• Entrepreneurial, adaptable, and resourceful
• Excited to build a new lab and diagnostic technologies from scratch
• Mission‑driven and collaborative

The estimated base salary range for this position is $125,000 – $160,000 (USD).

Mid‑Senior level

Full‑time

Research, Analyst, and Information Technology

Biotechnology