Dialysis Tubing

Dialysis is a technique that uses a semipermeable membrane to allow low-molecular-weight solutes to diffuse from a high-concentration solution to a low-concentration solution until equilibrium is reached. In protein research, it is used in a variety of applications, including the removal of low-molecular-weight substances, protein concentration, desalting, and buffer exchange. For dialysis, regenerated cellulose membranes are commonly used because they exhibit low protein adsorption and high chemical and thermal stability. Dialysis tubing is manufactured by forming dialysis membranes, such as regenerated cellulose membranes, into a tubular shape. Dialysis can be carried out by loading the sample into the tubing, sealing it, and immersing it in an external solution.

The most important parameter in selecting dialysis tubing is the molecular weight cut-off (MWCO). MWCO is generally defined as the molecular weight below which molecules are retained within the dialysis tubing at a level of 90% or higher. Conversely, molecules with molecular weights below the MWCO can pass through the dialysis membrane. However, because actual permeability is influenced by factors such as molecular shape, degree of hydration, and charge, it is recommended to select a dialysis membrane with an MWCO less than half the molecular weight of the substance to be retained. For protein dialysis, membranes with an MWCO of 12,000–14,000 are commonly used.

Fujifilm Wako offers dialysis tubing made from regenerated cellulose membranes, including Dialysis Membrane and Seamless Cellulose Tubing. Users can select the appropriate dialysis tubing based on parameters such as molecular weight cut-off (MWCO) and volume capacity.

Note: The size number in the product name indicates the diameter. For example, size 8 corresponds to a diameter of 6.35 mm, calculated as 25.4 mm (1 inch) x 8/32.