APPARATUS, SYSTEMS, AND METHODS FOR ISOTOPE EXCHANGE AND/OR DIALYSIS
A device for rapid dialysis of microliter volume liquid samples useful in laboratory-scale dialysis operations.
In dialysis, molecules and ions smaller than the molecular weight cut-off of a semi-permeable membrane will migrate across the membrane in response to a concentration gradient via the process of passive diffusion. Passive diffusion relies on the random motions of molecules and ions in the solvent. By this means, unwanted sample components may be replaced with the desired sample components. Dialysis is used widely in research laboratories as a sample preparation tool. A common operation in biochemistry labs is a buffer exchange where the buffer components of a biomolecule sample are replaced with different buffer additives. However, passive diffusion is slow, typically requiring hours to complete. Furthermore, most devices for dialysis require milliliter or larger volumes of sample.
The technology is useful in laboratory-scale sample preparation, such as buffer exchange by dialysis, often used in the preparation of protein samples in biochemistry labs.
How it works:
The invention uses commercially-available dialysis membranes integrated into a sample holder. In this device, small volumes of the sample and a dialysate are loaded into the device. The sample is applied as a thin liquid film. Because the liquid film is thin, diffusion into and out of the sample is completed rapidly.
This technology has two important advantages over existing tools for dialysis. First, dialysis can be completed much more quickly. Second, the device enables dialysis of microliter-sized samples.
Why it is better:
By applying the sample as a thin layer, the time required for complete exchange between the sample and dialysate is much faster.
In addition to its utility in sample purification, this device can also be used for hydrogen exchange analysis. The device enables the rapid exchange of heavy water (deuterium oxide) in the dialysate with water in the sample. The rapid exchange allows for biophysical analysis of protein samples using the established method of hydrogen exchange mass spectrometry without dilution of the sample that is usually required.