Bioconjugation Scientist

Discover International; Philadelphia (Philadelphia County); On-site; USD 55,000 - 83,000; Full time

Job summary

Discover International is seeking a Bioconjugation Scientist for a 3-month, hands-on, lab-based role in Philadelphia. The position focuses on protein purification, bioconjugation chemistry, and analytical characterization to support protein-toxin and siRNA-conjugate programs.

The ideal candidate has 5–8 years of industry lab experience, strong chromatography skills, and can work independently in a fast-paced environment.

Qualifications

• Hands-on bioconjugation and protein purification experience essential.
• Experience with protein-toxin or ADC-like conjugates preferred.
• Familiarity with siRNA or oligonucleotide conjugation is desirable.
• Ability to work independently in a fast-paced lab setting.

Responsibilities

• Purify recombinant proteins and bioconjugates using affinity, IEX, and SEC.
• Perform bioconjugation to generate protein-toxin conjugates.
• Conjugate siRNA payloads to protein vehicles for programs.
• Support analytical development and characterize proteins and conjugates.
• Maintain ELN documentation and lab records.
• Troubleshoot experiments and communicate results clearly.
• Collaborate across process development and analytical teams.
• Maintain equipment and inventory while following safety standards.

Skills

Bioconjugation chemistry

Protein purification

Analytical characterization

Independent bench work

Contract experience

Education

B.S. or M.S. in Biochemistry, Chemistry, Chemical Engineering, Molecular Biology, or related life sciences

Tools

FPLC/AKTA systems

SDS-PAGE

SEC-HPLC

RP-HPLC

Job description

Our client is seeking a temporary, lab-based Bioconjugation Scientist to join our Protein Sciences team for an initial 3-month contract, with the potential to extend based on program needs. This is a hands-on, bench-based role for an experienced scientist who is comfortable working independently at the lab bench on protein purification, bioconjugation chemistry, and analytical characterization in support of Client's protein-toxin conjugate and siRNA-conjugate programs. The ideal candidate is a self-starter who can step in quickly, execute experiments with minimal ramp-up, and contribute to a fast-paced, deadline-driven research environment.

Key Responsibilities

• Perform protein purification of recombinant proteins and bioconjugates using chromatography techniques such as affinity, ion-exchange, and size-exclusion chromatography (FPLC/AKTA systems).
• Execute bioconjugation reactions to generate protein-toxin conjugates, including conjugation chemistry optimization, reaction monitoring, and purification of conjugated species.
• Conjugate siRNA and other oligonucleotide payloads to protein targeting vehicles, supporting both proprietary and partnered programs.
• Support analytical development activities, including assay execution and characterization of proteins and conjugates (e.g., SDS-PAGE, SEC-HPLC, RP-HPLC, LC-MS, UV-Vis, and related techniques).
• Maintain detailed, accurate laboratory records and electronic lab notebooks (ELN) in compliance with good documentation practices.
• Troubleshoot experiments, analyze data, and communicate results clearly to project team members and stakeholders.
• Collaborate cross-functionally with process development, analytical, and discovery biology teams to advance conjugate candidates.
• Maintain lab equipment, reagent inventory, and adhere to all laboratory safety and quality standards.

Qualifications

• B.S. or M.S. in Biochemistry, Chemistry, Chemical Engineering, Molecular Biology, or a related life sciences discipline.
• 5–8 years of relevant, hands-on industry laboratory experience in a biotech, pharma, or CDMO/CRO setting.
• Demonstrated hands-on experience with protein purification and chromatography (FPLC/AKTA, affinity, IEX, SEC).
• Direct experience with bioconjugation chemistry; experience generating protein-toxin conjugates (e.g., ADC-like or similar payload conjugation) strongly preferred.
• Experience with siRNA or other oligonucleotide conjugation techniques is highly desirable.
• Working knowledge of analytical development and characterization techniques (SEC-HPLC, RP-HPLC, LC-MS, SDS-PAGE, UV-Vis, or similar).
• Comfortable working independently at the bench in a fast-paced, lab-based, full-time on-site role.
• Strong organizational skills, attention to detail, and clear written/verbal communication of experimental results.
• Prior experience in a small-biotech or start-up environment is a plus.