I have some questions about size exclusion and packing for the columns. First, i there a way to conduct an experiment using gravity fed column rather thn HPLC? 2nd where can I find some info about the different types of materials that can be used to pack a column? I want to do run a column on a polyphenol with a size range between 2 and 40 nm using THF as a solvent. If anyone has any ideas let me know.