Principal Scientist Assay Development Jobs (NOW HIRING)

Job DescriptionSenior Principal Scientist - Boston, MAOverviewWe are seeking a Senior Principal Scientist to provide scientific and strategic leadership for mass spectrometry-enabled discovery within the Quantitative Biosciences group in Boston. This role will help shape the application of mass spectrometry and quantitative pharmacology across discovery programs, strengthen experimental decision-making, and advance high-impact science through close partnership with local and global teams.As a senior scientific leader in Quantitative Biosciences, you will lead the Boston mass spectrometry capability supporting in vitro and in vivo pharmacology, advise multidisciplinary project teams, and influence broader QB strategy. The successful candidate will combine deep technical expertise in mass spectrometry-based assay development with strong pharmacology insight, sound scientific judgment, and the ability to mentor scientists and drive cross-functional alignment.In this role, you will:Lead the Boston mass spectrometry group in support of in vitro and in vivo pharmacology needs and serve as a key scientific partner to discovery teams across QB.Shape strategy for mass spectrometry-enabled assay development, experimental design, data interpretation, and quantitative pharmacology applications across discovery programs.Partner with multidisciplinary project teams to develop and execute mass spectrometry-based assays that inform mechanism, potency, selectivity, exposure-response, and translational decision-making.Provide scientific guidance to bench scientists and project teams, supporting assay selection, study design, mechanistic interpretation, and data-driven recommendations.Build and strengthen connections across the local Boston team and broader global QB network to ensure consistency, rigor, and effective deployment of mass spectrometry capabilities.Foster a culture of scientific rigor, critical thinking, collaboration, inclusion, and open dialogue that elevates organizational capability and decision quality.Mentor and develop scientists by providing technical guidance, strategic perspective, and constructive scientific challenge.Communicate effectively in a highly collaborative, multi-disciplinary environment and influence decisions across organizational boundaries.EducationPh.D. or equivalent in biology, pharmacology, analytical chemistry, biochemistry, pharmaceutical sciences, or a related STEM discipline AND 12+ years of relevant experience in a pharmaceutical, biotechnology, or closely related research setting; MS and 15+ years of experience; OR BS and 16+ years of experienceRequired Experience and SkillsDeep expertise in mass spectrometry-based assay development and application to drug discovery.Strong understanding of the drug discovery process, including hit finding, hit-to-lead, lead optimization, and pharmacology-driven decision-making.Demonstrated experience applying quantitative pharmacology principles to interpret biological systems and guide experimental strategy.Proven record of scientific leadership in a biopharmaceutical setting, with evidence of impact on discovery programs, publications, external scientific reputation, or internal platform advancement.Experience leading, managing, mentoring, or developing scientists in a research environment.Track record of independently designing experiments, interpreting complex data, and translating findings into clear project recommendations.Ability to simplify complex scientific challenges into actionable strategies and influence alignment across multidisciplinary teams.Excellent written and verbal communication skills, with the ability to present scientific concepts clearly to technical and non-technical stakeholders.Highly self-motivated, organized, and able to prioritize across multiple simultaneous projects.Experience integrating mass spectrometry readouts with pharmacology, biology, DMPK, or translational science to support discovery decisions.Demonstrated ability to work across sites, functions, and organizational boundaries to drive scientific consistency and impact.#EligibleforERPRequired Skills: Assay Development, Hit to Lead, In Vitro Pharmacology, In Vivo Pharmacology, Lead Optimization, Mass Spectrometry (MS), PharmacologyPreferred Skills: Current Employees apply HERE Current Contingent Workers apply HERE US and Puerto Rico Residents Only:Our company is committed to inclusion, ensuring that candidates can engage in a hiring process that exhibits their true capabilities. Please click here if you need an accommodation during the application or hiring process. As an Equal Employment Opportunity Employer, we provide equal opportunities to all employees and applicants for employment and prohibit discrimination on the basis of race, color, age, religion, sex, sexual orientation, gender identity, national origin, protected veteran status, disability status, or other applicable legally protected characteristics.--As a federal contractor, we comply with all affirmative action requirements for protected veterans and individuals with disabilities.- For more information about personal rights under the U.S. Equal Opportunity Employment laws, visit:EEOC Know Your Rights EEOC GINA Supplement• We are proud to be a company that embraces the value of bringing together, talented, and committed people with diverse experiences, perspectives, skills and backgrounds. The fastest way to breakthrough innovation is when people with diverse ideas, broad experiences, backgrounds, and skills come together in an inclusive environment. We encourage our colleagues to respectfully challenge one another's thinking and approach problems collectively.Learn more about your rights, including under California, Colorado and other US State Acts The salary range for this role is $214,100.00 - $337,000.00This is the lowest to highest salary we in good faith believe we would pay for this role at the time of this posting. An employee's position within the salary range will be based on several factors including, but not limited to relevant education, qualifications, certifications, experience, skills, geographic location, government requirements, and business or organizational needs.The successful candidate will be eligible for annual bonus and long-term incentive, if applicable.We offer a comprehensive package of benefits.- Available benefits include medical, dental, vision healthcare and other insurance benefits (for employee and family), retirement benefits, including 401(k), paid holidays, vacation, and compassionate and sick days. More information about benefits is available at https://jobs.merck.com/us/en/compensation-and-benefits .You can apply for this role through https://jobs.merck.com/us/en (or via the Workday Jobs Hub if you are a current employee). The application deadline for this position is stated on this posting. San Francisco Residents Only: -We will consider qualified applicants with arrest and conviction records for employment in compliance with the San Francisco Fair Chance Ordinance Los Angeles Residents Only: -We will consider for employment all qualified applicants, including those with criminal histories, in a manner consistent with the requirements of applicable state and local laws, including the City of Los Angeles' Fair Chance Initiative for Hiring Ordinance Search Firm Representatives Please Read Carefully-Merck & Co., Inc., Rahway, NJ, USA, also known as Merck Sharp & Dohme LLC, Rahway, NJ, USA, does not accept unsolicited assistance from search firms for employment opportunities. All CVs / resumes submitted by search firms to any employee at our company without a valid written search agreement in place for this position will be deemed the sole property of our company. -No fee will be paid in the event a candidate is hired by our company as a result of an agency referral where no pre-existing agreement is in place. Where agency agreements are in place, introductions are position specific. Please, no phone calls or emails.-Employee Status: RegularRelocation:Domestic/InternationalVISA Sponsorship:Yes Travel Requirements: No Travel RequiredFlexible Work Arrangements:Not ApplicableShift:Not IndicatedValid Driving License:NoHazardous Material(s):n/aJob Posting End Date:09/25/2026 *A job posting is effective until 11:59:59PM on the day BEFORE -the listed job posting end date. Please ensure you apply to a job posting no later than the day BEFORE the job posting end date. Requisition ID:R415648 Salary: . Date posted: 09/05/2026