For simple dialysis of small volumes
These mixed cellulose esters membrane discs are a convenient, high recovery way to dialyze micro-volumes of protein or nucleic acid solutions (<100 µL). With the “drop dialysis” technique, a floating filter disc replaces the dialysis sac.
Recoveries of DNA and protein samples have been reported in excess of 98% (Marusyk, R. and Sergeant, A., “A Simple Method for Dialysis of Small-Volume Samples,” Analytical Biochem. 105, pp. 403–404, 1980).
Drop Dialysis Technique
1. Fill the bottom of a Petri dish with buffer.
2. Float the membrane filter disc on the surface of the buffered solution.
3. Deposit 5–100 µL of sample on the center of the membrane. Place a tight-fitting lid on the Petri dish to prevent evaporation.
Marker dyes may help in determining the dialysis time required. Most samples are dialyzed in less than 30 minutes.
4. Recover the desalted sample.
