At CellMosaic, we go the extra miles to take care of customers' projects. There are many exploratory, challenging, and unconventional drug conjugation projects we have done for our customers. For example:
Drug conjugates involving three or more types of molecules, such as protein-antibody-dye conjugates, peptide-antibody-dye conjugates, protein-protein-dye conjugates, for drug assay development are prepared at CellMosaic. Here, the protein or peptide acts as a delivery vehicle while the antibody or other protein is a therapeutic agent. The dye helps track the delivery of the therapeutic antibody or protein using a fluorescent imaging technique. The fluorescent dyes are first loaded onto the antibody or protein with DOL at the customers' specification. Then we use controlled reaction conditions plus advanced purification techniques to obtain a 1:1 ratio of protein and antibody/protein-dye conjugates. There is minimum aggregation during the conjugation and 10-20% overall recovery yield for such high-quality complex conjugates.
Example 1: Preparation of Protein-mAb(AF647)4.5 and Peptide-mAb(AF647)4.5 conjugates.
Example 2: Preparation of Protein 1-Protein 2(AF680)3.6 conjugates (Protein 1: delivery protein, Protein 2: a therapeutic fusion protein).
Preparation of Lipid-PEG-Fab' conjugate at CellMosaic. We developed a process to produce F(ab')2 from IgG in high yield (over 50% recovery after purification). The Fab' fragment is highly unstable and presents a challenge during conjugation and storage.