As of 2020, FDA recommends a reliable and continuous source of antibody production based on master cell banks for cell cultures, seed banks for transgenic plants, or founder strains for transgenic animals. Purification steps include eliminating animal proteins, DNA, endotoxin, along with robust virus removal and inactivation steps. Characterization of mAbs typically consists of utilizing a combination of SDS-PAGE, IEF, HPLC, and mass spectrometry analytical methods with reference standards to ensure mAb purity .