In the set of Protein Specs filters we designed for protein products in the AI-Assisted Reagent Selection application, you will find two that at first appear similar, Modification and PTM (post-translational modification). PTM relates specifically to modifications of the protein by (but not exclusively):
You can also filter by which specific residue is modified, for example, Lysine 9 of human histone H3.
Modification, however, refers to tags (e.g. His, GST, Fc, etc.), conjugates (e.g. fluorescein, biotin, etc.), or reporter proteins (GFP, alkaline phosphatase, peroxidase) that decorate your protein of interest for purposes related to the experiment.
Please check out our Guide to Filters for Protein Reagents to learn more about our filters!