送交者: Godfather 于 2006-1-23, 20:04:37:
回答: 高发得(Godfather)的看法很有见地 由 桂铭 于 2006-1-23, 13:57:27:
It just depends on the time of dialysis length and the time of buffer change, which ususally is not efficient since the the dialyszing tubes keep the same volume (oftern, volume has been increased during dialysis) and the quality of dialyzing tubes are not satisfactory. That's why nowaydays people use ultrafiltration instead. Even if one uses ultrafiltration, the membranes cannot gurantee the removal of small molecules. Foe example, if you use a 100kD cut-off membrane to removal a 10kD contaiminant, after 2-3 cycles, the 10kD contaminant still there up to 20%. Of course, it depends on the starting volume, the volume of additional buffer and the cycles of buffer change. Final volume is another factor for the final concentration of small molecules. Just some hands-on experience.