Equilibrium Dialysis with microdialysis cells.

Micro-diffusion Cells.

M P O D T	- Microdialysis button - Protein - Outer solution - Dialysis membrane - Tubing

Buttons made out of glass, perspex or Teflon.

The volume of the cell is between 5 and 350 microliter.

(A) The cell is filled with the protein sample.

(B) The applicator with O-ring and the dialysis membrane is placed quickly over the cell, to prevend air bubbles in the cell.

(C) The dialysis membrane is fixed in place with the O-ring.

(D) The applicator is removed and the button in placed in a well filled with mother liquor. The well is closed with a coverslide or sealing tape.

Double dialysis method.

M P O I D T	- Microdialysis button - Protein - Outer solution - Intermediate solution - Dialysis membrane - Tubing

A button containing the protein solution, sealed with a dialysis membrane, is placed in a small vail containing an intermediate solution, with a precipitant concentration insufficient to crystallize the protein. This vial is sealed with a dialysis membrane and placed in a larger vial which contains the outer solution, containing precipitant at a higher concentration which is sufficient to precipitate the protein. The rate of dialysis is varied by changing the relative volumes of the compartments and the solution concentrations.[Thomas, 1989]