Calibration curves for size-exclusion chromatography: description of HPLC gels in terms of porous fractals.

We have tested the proposition that porous media used in protein size exclusion chromatography are surface fractals. The data obtained in the calibration of classical gels (Sephacryl and Sepharose) and of HPLC gels (TSK SW and PW) using a wide range of protein sizes, have been analyzed within the framework of this theory. While the model does not apply to classical gels, it seems that HPLC gels can be described as fractals in the range of protein sizes. This finding has interesting implications for the calibration procedure.