Scientist/Senior Scientist, Assay Development - Molecular Assay Chemistry and Biophysics

Spear Bio Inc.; Woburn (MA); On-site; USD 120,000 - 160,000; Full time

Job summary

Spear Bio Inc. in Woburn, MA seeks a Scientist/Senior Scientist in Assay Development to design and optimize ultrasensitive protein-detection assays. The role requires hands-on chemistry, biophysics, and molecular interactions expertise, and strong problem-solving in a fast-moving startup.

You will work onsite five days a week, develop antibody and reagent sets, troubleshoot issues, and document findings for publications and internal transfer. Ph.D.

Qualifications

• Ph.D. in Chemistry, Analytical Chemistry, Biophysics, Chemical Engineering, Biochemistry, Bioengineering, Molecular Engineering, or a closely related field.
• Strong fundamental understanding of molecular interactions involving nucleic acids, proteins, or both.
• Experience with protein–protein and antigen–antibody interactions, including affinity, avidity, kinetics, and thermodynamics.
• Hands-on experience creating and designing immunoassays, protein-detection methods, molecular-diagnostics assays, or related platforms.
• Strong experimental-design and troubleshooting skills; able to test mechanistic hypotheses efficiently.
• Ability to work independently, analyze complex data, and make sound technical decisions.
• Evidence of meaningful scientific contributions through publications, patents, or talks; strong written/verbal communication.
• Willingness to work onsite five days per week in Woburn, MA; relocate if needed.

Responsibilities

• Design and develop ultrasensitive protein-detection assays from concept to transfer.
• Develop and optimize antibody and protein reagents to maximize performance.
• Troubleshoot assay performance issues using mechanistic understanding of kinetics and interactions.
• Design efficient experiments and use DOE to identify root causes and optimize performance.
• Collaborate with Platform, Product Development, Operations, and BD teams to enable transfer.
• Prepare clear scientific presentations, technical reports, and publications.

Skills

Analytical thinking

Troubleshooting

Independent work

Scientific communication

Education

Ph.D. in Chemistry

Job description

Spear Bio, founded in 2021, is a well-funded and rapidly growing biotech start-up headquartered in Woburn, Massachusetts. Our proprietary technology,Successive Proximity Extension Amplification Reaction (SPEAR), is an novel wash-free immunoassay platform, offering unprecedented sensitivity. We are dedicated to revolutionizing early disease diagnosis and monitoring by providing scalable, ultrasensitive solutions that deliver unparalleled accuracy in measuring low-abundant biomarkers, enabling clinicians and researchers to improve patient outcomes and advance global health.

Scientist/Senior Scientist, Assay Development - Molecular Assay Chemistry and Biophysics

Our Assay Development team builds assays for low-abundance protein biomarkers that are challenging to measure using conventional approaches. We are seeking a creative, hands-on scientist with strong fundamentals in chemistry, biophysics, and molecular interactions who enjoys solving difficult technical problems from first principles.

The Scientist / Senior Scientist will design, optimize, and troubleshoot innovative protein-detection assays that integrate antibody-based recognition, nucleic-acid interactions, conjugation chemistry, reaction kinetics, and quantitative analytical methods.

We are looking for a scientist who genuinely enjoys troubleshooting. The ideal candidate is persistent, analytical, creative, and comfortable working through uncertainty. This person should be motivated by understanding the underlying mechanism and should thrive in a fast-moving startup environment with high scientific standards.

The successful candidate will be comfortable investigating why an assay behaves unexpectedly, developing mechanistic hypotheses, designing discriminating experiments, and systematically improving assay sensitivity, specificity, robustness, and reproducibility.

We welcome applications from exceptional recent Ph.D. graduates and postdoctoral fellows with strong hands-on research ownership, as well as startup and industry scientists who have demonstrated rapid growth in technical scope and responsibility. **This role is based onsite in our lab in Woburn, MA 5 days/week.

Responsibilities:

• Design and develop ultrasensitive protein-detection assays from concept through feasibility, optimization, analytical characterization, verification, and transfer.
• Develop and optimize antibody and protein-reagent to maximize analytical and clinical performance, including antibody selection, protein structural properties, epitope-pair assessment, conjugation chemistry, reagent purification, and stability evaluation.
• Troubleshoot assay-performance issues, including low signal, nonspecific background, limited sensitivity, poor reproducibility, matrix effects, instability, and lot-to-lot variability, using a mechanistic understanding of binding kinetics, affinity, avidity, thermodynamics, steric effects, and molecular interactions.
• Design efficient experiments and use structured approaches, including design of experiments where appropriate, to identify root causes and optimize performance.
• Collaborate closely with Platform, Product Development, Operations, and Business Development teams to transition assays from feasibility through verification and transfer.
• Prepare clear scientific presentations, technical reports, study summaries, abstracts, and publications.

Requirements:

• Ph.D. in Chemistry, Analytical Chemistry, Biophysics, Chemical Engineering, Biochemistry, Bioengineering, Molecular Engineering, or a closely related field.
• Strong fundamental understanding of molecular interactions involving nucleic acids, proteins, or both.
• Experience with protein–protein and antigen–antibody interactions, including affinity, avidity, kinetics, and thermodynamics.
• Demonstrated hands-on experience creating and designing immunoassays, protein-detection methods, molecular-diagnostics assays, or an innovative life-science analytical platform.
• Strong experimental-design and troubleshooting skills, with the ability to develop mechanistic hypotheses and test them efficiently.
• Demonstrated ability to work independently, analyze complex data, and make sound technical decisions. · Evidence of meaningful scientific contributions through peer-reviewed publications, patents, conference presentations, or platform-development programs. · Strong written and verbal communication skills. · Ability to work onsite five days per week in Woburn, Massachusetts. Candidates must be based in the Greater Boston area or able to relocate before the start date.
• Can work 5 days/week on site in Woburn, MA .

We offer competitive compensation, meaningful stock ownership, comprehensive benefits, and a great work environment. This is an opportunity to enter an innovative, high-growth startup at an early stage and play an integral role in the company's growth and success. We are focused on identifying candidates who have demonstrated leadership and excellence throughout their careers and are excited by the prospect of building an industry-leading company.

Spear Bio Inc. provides equal opportunity in employment to all persons. No person shall be denied equal access because of race, creed, color, religion, national origin, sex, sexual orientation, gender identity, age, or physical/mental disability.

Spear Bio does not accept resume submissions from external recruiting agencies. Any unsolicited resumes or candidate information submitted without prior written agreement will be deemed the property of Spear Bio, and no placement fees will be paid.