University:
The Pennsylvania State University
Course:
BMB 443W | Laboratory in Protein Purification and Enzymology
Academic year:

2024
Views:

163

Pages:

2
Author:

Alexis H.

Ultra Ultra ltration ltration Ultrafiltration is a process that separates extremely small particles and dissolved molecules from fluids. The primary basis for separation is molecular size, although filter permeability can also be affected by the chemical, molecular or electrostatic properties of the sample Ultrafiltration is typically used to: Separate proteins from buffer component for buffer exchange, desalting, or concentration Remove or exchange sugars Remove or exchange non-aqueous solvents Separate free and protein-bound ligands Remove materials of low molecular weight Rapidly change ionic and/or pH environment Ultrafiltration membranes are regenerated cellulose membranes, have two layers: 1. A thin (0.1-1.5 um), dense skin with pore diameters of 10-400 angstroms 2. A highly porous substructure. Unlike the porous substructure, the dense cellulose-based skin enables precise molecular weight cut-offs doe to its highly controlled and precise pore size Dialysis is typically used when: Ultrafiltration is typically used when: Samples precipitate at high concentrations Slow solvent exchange needed Samples don't require concentration Samples won’t precipitate at high concentrations Fast solvent exchange needed Samples need to be processed at cold temperatures This filter provides fast sample processing, with high sample recovery (usually over 90% of the diluted starting solution) and the capability for an 80-fold concentration

Ultra Filtration