With 30 years of expertise, Marin Bio’s protein/antibody services focus on the delivery of quality data to support every stage of the product development lifecycle from expression to purification to bioactivity measurement for development, qualification/validation, through IND and NDA/BLA stages and for commercial pharmaceuticals.

Our Commitment to Excellence

  • Innovative Protocols
  • Prompt timeliness
  • Cost-effective solutions
  • Unmatched quality
  • Exceptional communication

We interact directly with the FDA, ensuring regulatory compliance and supporting our clients at every step.

Proteins are large biomolecules with one or more long chains of amino acids, think meat, insulin, antibodies, Ozempic.  Proteins have many functions, such as structure (collagen, muscle), enzymes that carry out chemical reactions (DNA syntheses), or messenges (growth hormone).

MarinBio’s scientists have expertise in cloning, protein production, purification, and characterization. Whether your project involves the expression and purification of recombinant proteins using bacteria, yeast, cell-free expression systems, baculovirus, and mammalian cells, we can help you.

We provide comprehensive services in developing functional cell-based assays, ELISA, Flow cytometry services, cellular immunoassays, stability studies, and lot release assays.

Need Help or Have Questions on Protein/Antibody Cloning, Expression, Purification and Characterization

Contact us to discuss the specifics of your project. Our team of experienced scientists is ready to assist you with tailored solutions to meet your unique needs. Whether you need help with assay development, FDA IND, stability study,  lot release approval, or other scientific endeavors, we are here to support you.
Contact us to learn more about our cell based assay services

We will initiate your project as soon as the proposal is approved and signed by you. Our streamlined process ensures a quick start, minimizing delays and maximizing efficiency. Fill out the form below to email us or click our live chat option to speak with a MarinBio Scientist and get your project underway.

Yes, we have over 30 years of expertise in developing and validating cell based assays for FDA IND, lot release or stability study approval. Our team can also liaise directly with the FDA on your behalf, ensuring a smooth and compliant process. Please contact us to learn more about how we can assist you with your assay development and FDA approval needs.

MarinBio scientists are experienced and creative in designing, developing, validating assays. Some of the assays we perform are listed below, but there are many more that we created, developed and validated. Give us call so that we may help you.

Need help or have questions on cell based assays?

Give us a call at 415-883-8000

Our Protein/Antibody Service Include:

We offer comprehensive services under one roof, providing everything needed to progress your

antibody or protein drug from concept to FDA approval. Our unique advantage lies in our extensive

capabilities, which include:

  • Cloning and Expression, including codon optimization / humanization of antibodies.
  • Purification, including GMP antibody purification.
  • Development of in vitro functional assays for proteins
  • Development of cell-based assays, ELISA, and cellular immunoassays
  • Stability studies and lot release assays
  • Molecular biology techniques, including PCR, Western blotting, and transfections
  • GMP potency bioassays and GLP assays
  • Immunogenicity and neutralizing antibody assays

Case Studies:

Purification of Recombinant Proteins Expressed in Mammalian Cells

HEK 293 cells were adapted for suspension culture and transfected with a DNA plasmid. After 4 days the supernatant media was harvested, and the expressed recombinant protein purified by binding to a Protein L column. Elution of the protein was followed by absorbance at 280nm. Characterization of the protein pool was performed on SDS-PAGE, and the purified protein showed the expected molecular weight.


Expression, Purification and Characterization of a Recombinant Bispecific Antibody

The DNA plasmid containing the bispecific antibody gene was transfected into suspension culture HEK 293 cells. The expressed bispecific antibody was then purified using affinity chromatography and characterized by SDS-PAGE analysis for purity and by ELISA for bispecificity.

Bispecific antibody purification                         Bispecific antibody ELISA method 

                   The ELISA has a sensitivity of 60 pg/mL in neat serum.



Functional Analysis of Purified Recombinant Bispecific Antibody

A cell-based potency assay has been developed for the functional analysis of recombinant bispecific antibodies that MarinBio purified. The bispecific antibody binds killer T-cells to a cancer cell line (preloaded with a fluorescent dye). The killing of cancer cells is measured when the dye is released from the cancer cells (see figure below). Increasing concentrations of the bispecific antibody are added and the culture is incubated for 2.5 hours. With increased concentration of the bispecific antibody, more killing occurs releasing more fluorescent dye (see graph below).


Contact Us about Our Cell Based Assays Services

For More Information about our cell based assay services, please use the following informational form