675 US Highway 1, Suite B129, North Brunswick, NJ 08902

Bioconjugation Services

Our bioconjugation services include the following:

  • Design and synthesis of potent cytotoxic compounds, linkers, and payload-linker constructs.
  • Preparation and purification of bioconjugates from milligram- to gram-scale.
  • Modification of carbohydrates, polysaccharides, and glycoconjugates.
  • Preparation of fluorescent probes.

Conjugation methods employed at NJ Biopharmaceuticals include:

  • Cysteine conjugation
  • Lysine conjugation
  • Conjugation to engineered cysteines and non-natural amino acids
  • Enzymatic conjugation


Express Conjugation Services using Lysine and Cysteine Conjugations:

This expeditious service will require the client to supply the monoclonal antibody to NJ Biopharmaceuticals.

Amounts needed:

  • 5 – 20 mg of mAb for preparation of 3 – 10 mg of ADC.
  • Unused amounts of antibody will be returned to client.


  • The well-characterized ADCs, typically with a drug-to-antibody ratio (DAR) in the range of 3 – 5, will be supplied in the desired formulation buffer.
  • ADCs will be characterized for:
    • DAR by HIC or rp-HPLC and MS
    • Monomer content by SEC
    • Concentration by UV
    • Residual linker-payload by LC-MS
    • Endotoxin by LAL assay

Protoxins for ADC

NJ Biopharmaceuticals is developing Protoxins for antibody-drug conjugates (ADCs). For more detail, please contact us at

Pro Toxins Banner


The following is a listing of our core and niche chemistry and biology services

Chemistry Services

  • Protein- and antibody-drug conjugates
  • Synthesis of toxins and cytotoxic drug molecules
  • Linker chemistry
  • PEGylation
  • Medicinal chemistry for biopharmaceuticals
  • Custom synthesis of small molecules
  • Process development for small molecules
  • Flow chemistry custom synthesis
  • Design of flow chemistry equipment

Biology Services

  • Cell-based functional assays including cytotoxicity assays
  • Research-grade protein and antibody manufacturing
  • Protein purification and characterization

Payloads and Linkers for Antibody-Drug Conjugates

Payloads: NJ Biopharmaceuticals has a variety of highly potent warheads/payloads in stock for advancing its clients’ ADC programs. The following is a list of several classes of payloads in our toolbox for preparing ADCs or protein drug conjugates (PDCs):

  • PBD dimer analogs
  • Duocarmycin analogs
  • Auristatin analogs
  • Maytansine analogs
  • Exatecan and SN-38 derivatives
  • Additional payloads (details available on request)


Linkers: Antibody-drug conjugates (ADCs) are comprised of an antibody to which typically a cytotoxic agent is attached through a linker. The type of linker chemistry used significantly affects the potency, selectivity, and pharmacokinetics of the resulting ADC. NJ Biopharmaceuticals can offer a variety of linkers tailored for specific proteins and targets. These linkers will be selected based on the type of protein, antibody and desired release mechanism for drug molecules keeping long-term stability of the protein as one of the priorities. A selection of cleavable and non-cleavable linkers and spacer molecules is available.


NJ Biopharmaceuticals can offer PEGylation services for proteins and small molecules to significantly improve the physicochemical properties of a drug, extend the half-life time, increase the solubility of poorly soluble molecules, and reduce the immunogenicity of biopharmaceuticals. The following is a list of the offered services:

  • Protein PEGylation
  • Peptide PEGylation
  • Antibody PEGylation
  • Small molecule PEGylation
  • Purification of PEGylated products
  • Process development of PEGylated products
  • Custom synthesis of PEGs
  • Development of PEGylated biosimilars

Custom Synthesis of Small Molecules

NJ Biopharmaceuticals’ team of experienced organic chemists can tackle the synthesis of complex molecules, including chemical intermediates, drug metabolites, process impurities, degradants, reference compounds, preclinical drug candidates, and other organic molecules from diverse industries.

Our custom synthesis expertise includes:

  • Carbohydrates (including glucuronides)
  • Catalytic hydrogenations
  • Chiral synthesis and separations
  • Flow chemistry
  • Macrolides
  • Metabolites/ Impurities
  • Nucleosides and Nucleotides
  • Organic materials
  • Organometallic compounds
  • Oxidations
  • Peptide/amino acid synthesis
  • Polycyclic aromatic hydrocarbons
  • Photochemistry
  • Pressure reactions
  • Labelled compounds with stable isotopes including deuterium, 13C, 15N
  • Steroids
  • Suzuki, Stille, Buchwald-Hartwig and other coupling reactions
  • Sulfonylations
  • Toxic/potent compounds

Medicinal Chemistry

NJ Biopharmaceuticals can provide services to advance the drug discovery and development process from lead generation through scale-up. Specifically, our services include:

  • Lead generation
  • Lead optimization
  • Scale-up

The advantages of using NJ Biopharmaceuticals for your medicinal chemistry needs include:

  • Combination of experience and state-of-the-art facility to deliver clinical candidates
  • Rapid and efficient resource deployment to enable “first-to-file”
  • Seamless progression from LG/LO to scale-ups
  • Expertise in difficult protein-protein interaction inhibitors

    Process Development and Flow Chemistry

    NJ Biopharmaceuticals offers process development services for small molecules and protein manufacturing. In addition to traditional batch chemistry, NJ Biopharmaceuticals’ flow chemists have ample experience designing multi-step custom flow chemistry routes to drug intermediates and APIs.

    Our flow chemistry experts can help you design chemical reactions in continuous flow rather than batch, which offers many advantages including improved safety, better process control, and better heat transfer. In flow, it is possible to perform highly exothermic reactions in a safe and efficient manner.

    NJ Biopharmaceuticals provides its flow chemistry services in collaboration with Amar Chemistry Pvt. Ltd.

    • Flow chemistry process development
    • High-pressure chemistry process development
    • Medicinal chemistry
    • Impurities synthesis
    • Small scale API synthesis

    In addition, in collaboration with the flow chemistry experts at Amar Equipments Pvt. Ltd., we are able to design customized equipment for all your flow chemistry challenges.

    Purification and Analytical Services

    Our state-of-the-art purification lab is equipped with an array of analytical and preparative HPLC and FPLC instruments and columns, which allow us to handle the most difficult separations for small and large molecules, including antibodies and other proteins. In addition, our LC-MS and Q-TOF mass spectrometers and 300-MHz NMR spectrometer give us the capability to offer our clients valuable and reliable analytical data and along with these services. We are continually adding additional instrumentation and equipment in order to provide a seamless, uninterrupted operation.

    Our purification and analytical services include:

    • Analytical and preparatory HPLC method development
    • NMR analysis (300 MHz, 1H, 13C, 31P, 19F, multidimensional)
    • Size-exclusion/gel-filtration chromatography
    • LC-MS analysis
    • Chiral separations
    • Purity determinations by HPLC
    • Ion-exchange chromatography
    • Intact mass for protein and protein conjugates using mass spectrometry

      Molecular Biology

      NJ Biopharmaceuticals provides molecular biology services, including the preparation of expression plasmids for the production of both mammalian and bacterial recombinant proteins. Professional codon optimization ensures the highest expression levels. According to the client’s specific requirements, tagged or tag-free protein service are available for bacterial expression.

      Research Grade Protein and Antibody Manufacturing

      NJ Biopharmaceuticals can support the production of research-grade recombinant proteins, both mammalian and bacterial. Our experts can promptly identify and evaluate the best expression conditions for your protein, rapid expression of functional protein or antibody. Our preparation includes FPLC and HPLC analysis, QC detection using SDS-PAGE and Western blot. Other services, such as MS, are optional. We also provide service of expression and production of biosimilars in HEK293 and CHO cells.

      Cell Based Functional Assay including Cytotoxicity Assays

      NJ Biopharmaceuticals utilizes plate-based assays to characterize the ability of the compounds to promote or inhibit cell proliferation, establish the cytotoxicity of compounds by measuring live/dead cells. Assay optimization would include a time course of incubation and compound concentration analysis. Client will supply proteins for analysis. Functional assays include binding assays.

      Service Models

      Depending on the nature of the project, NJ Biopharmaceuticals offers its clients the following contract options:


      • Fee-For-Service:
        Weekly Fee: Client pays weekly fee for cost of labor plus cost of chemicals and materials
        Fixed Quote: Payment due on delivery only; labor and chemical costs included
      • FTE (Full-time equivalent) Basis:
        Client pays fixed monthly fee per chemist; general materials included; both short-term and long-term contracts possible
      • Milestone-based Service:
        Client pays NJ Biopharmaceuticals when certain milestones are achieved


        At its headquarters in North Brunswick, New Jersey, NJ Biopharmaceuticals currently occupies more than 4000 sq. ft. of laboratory space inside the CCIT, a leading technology park dedicated to life sciences and biotechnology.Read More


        We have highly talented and experienced laboratory chemists and biologists with a tremendous passion for chemistry and biology resulting in unique solutions to client programs. Furthermore, our corporate culture is collaborative, communicative, and adaptable. Most importantly, our scientists strive to deliver quality services in a cost-effective and timely manner.

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