Quick answers about LeviSelect
Frequently Asked Questions About LeviSelect Cell Depletion
1. What is the LeviCell platform and how does it separate cells?
The LeviCell platform is a technology that separates cells based on their physical properties, specifically density and magnetic susceptibility. Cells in a mixed population levitate to different equilibrium heights within the LeviCell cartridge based on these properties, allowing for separation.
2. What is a limitation of the LeviCell platform and how is it addressed by magnetic bead depletion?
A limitation arises when separating cell populations with very similar densities, as they will levitate to the same height. To overcome this, the LeviSelect system uses magnetic beads conjugated with antibodies to target specific cell surface proteins. When these beads bind to unwanted cells, they alter the magnetic properties of those cells. The LeviCell's magnets then attract these bead-bound cells, effectively depleting them from the desired cell population.
3. How does the LeviSelect Human CD45 Depletion Kit work?
This kit uses superparamagnetic nanospheres conjugated with an anti-human CD45 antibody. These beads bind to CD45-positive cells. When the cell mixture is loaded into the LeviCell, the magnets attract the bead-bound CD45-positive cells to the bottom and side walls of the cartridge, while the unbound CD45-negative cells levitate freely, allowing for their collection and enrichment.
4. What are the key advantages of using the LeviSelect system for cell depletion?
The key advantages include a simple workflow, no cell staining or labeling is required for the levitation step, gentle cell processing which minimizes stress on cells, and the ability to enrich a high viability desired cell population in a single process. The workflow for magnetic bead depletion is efficient and relatively quick, taking about 30 minutes.
5. How does the number of cells affect the separation process, and what is the maximum number of cells that can be processed?
While cell numbers don't impede the separation process, high cell numbers (>1M) can broaden the live and dead cell bands making distinction and thus precise separation slightly more challenging. However, the data indicates the LeviSelect Human CD45 Depletion Kit can process samples with up to 8 million CD45-positive cells without a significant loss in depletion efficiency or yield of the desired cells. It can enrich 1M CD45 negative cells up to a maximum of 9M cells loaded.
6. What are the typical depletion and yield rates achieved using the LeviSelect Human CD45 Depletion Kit, and how do they vary with cell number?
The data indicates a consistent depletion rate of approximately 99.6% for CD45-positive cells, with an average yield of around 60% for CD45-negative cells. These rates remain relatively stable even with increasing numbers of CD45-positive cells.
7. How does the initial purity of the sample affect the final purity of the depleted cell population?
The initial purity of the sample significantly impacts the final purity. Even with a high depletion rate, a small number of unwanted cells will still be present in the final sample. If the initial proportion of unwanted cells is high, they will represent a larger fraction of the final depleted population, resulting in a lower overall purity. Therefore, understanding the relative proportion of CD45Pos cells in the sample prior to depletion is important.
8. Is the LeviSelect system suitable for research or clinical use?
The document explicitly states, "For Research Use Only. Not for use in diagnostic procedures."