Dynamic dialysis: an efficient technique for large-volume sample desalting.

Dialysis is a well-known technique for laboratory separation. However, its efficiency is commonly restricted by the dialyzer volume and its passive diffusion manner. In addition, the sample is likely to be precipitated and inactive during a long dialysis process. To overcome these drawbacks, a dynamic dialysis method was described and evaluated. The dynamic dialysis was performed by two peristaltic pumps working in reverse directions, in order to drive countercurrent parallel flow of sample and buffer, respectively. The efficiency and capacity of this dynamic dialysis method was evaluated by recording and statistically comparing the variation of conductance from retentate under different conditions. The dynamic method was proven to be effective in dialyzing a large-volume sample, and its efficiency changes proportionally to the flow rate of sample. To sum up, circulating the sample and the buffer creates the highest possible concentration gradient to significantly improve dialysis capacity and shorten dialysis time.