Path length of macromolecule is important because as the size of molecules becomes larger, path length becomes shorter. For instance, DNP-amino acid has long path length, protein of interest has medium path length, and blue dextrin has short path length.
To determine molecular mass, spectrometry is used to monitor elution and is used to calculate Kd using (Ve-V0)/(Vt-V0), where Ve=elution volume for protein of interest, V0= void volume for Blue dextrin, and vt=total