The Rapid Desalting Dialyzer: Characterization of a Desalting Device

Abstract

In order to optimize mass spectral analysis of biological macromolecules, several

different techniques are currently used for desalting. Unfortunately, these techniques often require large amounts of material and can be time-consuming. The recent increase in analysis of DNA and other biomolecules using mass spectrometry has created the need for more efficient and specific desalting techniques. Bioanalytical Systems, Inc. has constructed the Rapid Desalting Dialyzer, a desalting device that uses a microdialysis membrane to remove low molecular weight molecules from samples. The device provides faster removal of small molecules than traditional dialysis membranes. This study characterizes the effects of different experimental conditions on the performance of the Rapid Desalting Dialyzer.

The goals of this study were to characterize the effect of perfusate and outer membrane flow rate on sample loss and salt depletion, determine the effect of molecular weight on compound loss, and characterize the loss of sample fluid under different flow conditions. The effect of flow conditions on fluid loss was found to be dependant on the type of sample used for perfusate flow. No trends were observed between the mass recovery of the sample fluid and molecular weight of the sample. The effect of molecular weight on compound recovery was also found to be variable. Under all conditions, the Rapid Desalting Dialyzer removed sufficient levels of sodium from the sample matrix.