In the creation of bio-pharmaceutical drugs, cells are genetically modified to produce some compound shown by research to have a desired effect in a treatment program. First there’s the genetic engineering to discover a compound and then how to modify a cell to produce the compound. Essentially the cell becomes a chemical factory secreting a certain compound. The cells are then grown in a manner similar to how beer is produced in vats called “bioreactors”.

These cells typically produce very big macro molecules (ranging in molecular weight from 50,000 to well over 100,000), most are proteins, some are peptides. This differs from traditional pharmaceuticals which are generally made from much smaller molecules.