The data from protein characterization studies are used to make crucial development decisions based on a thorough understanding of the structural attributes of a biopharmaceutical. For this reason, characterization or comparability studies are not performed to GMP, since they are not testing the product against a set specification. Characterization reports are supportive to a regulatory submission and therefore developers want to be confident that the data has been generated using scientifically sound protein characterization methods. Methods and instruments should be qualified and a meaningful and well-designed quality system should be implemented and followed. Standard Operating Procedures (SOP) should be in place and should be regularly monitored and updated.