Recombinant antibody expression service are used in a variety of biotechnological applications including protein-protein interactions, cell classification and detection, and therapeutics. They can be produced by several different systems including hybridoma cells, mammalian expression hosts (HEK and Chinese hamster ovary cells), baculovirus infection of insect cells, and transgenic animals and plants. Recombinant antibodies have the benefit of being highly characterized, as the antibody protein sequence can be analyzed with a variety of technologies such as DNA sequencing, liquid chromatography-tandem mass spectrometry (LC-MS/MS), and antigen capture.

The production of recombinant antibodies requires trained labour and a well equipped biotech laboratory, which includes cell culture incubators and consumables, molecular biology equipment, cell sorting, and protein purification and analysis tools. Often the antibody production process will begin with a biopanning phage display library which is then selected for binding to the target antigen of interest. This selection process generally occurs multiple times through panning, and the resulting phage-display clones are then analyzed for antigen recognition.

Recombinant Antibody Expression Services: What You Need to Know

Depending on the application, the recombinant antibody clones may be further characterized through additional methods such as SDS-PAGE and ELISA to assess their specificity and performance. Additionally, recombinant Fabs can be characterized via a technique known as de novo sequence characterization. This method isolates a portion of the protein cleaved off from the full length IgG, allowing it to be sequenced in the form of peptides.

Unlike hybridoma-derived antibodies, recombinant Fabs are stable and can be readily characterized by immunogold labeling for electron microscopy (EM) studies. They also have a number of advantages over full-length IgGs, such as the ability to generate conformationally-specific Abs through proteolytic cleavage and being easier to purify to milligram quantities for EM studies. Furthermore, the use of recombinant Fabs as fiducial markers for single-particle cryoEM has been an important step towards solving high-resolution structures of difficult-to-solve proteins41.