Accessible single human cells are integral to the development of cell therapies and other immunology research initiatives. There are many approaches for isolating cell populations of a single cell type from whole blood—although most are lengthy and impractical for large-scale research.
The most common of these approaches uses isolation of a peripheral blood mononuclear cell (PBMC)-rich sample via magnetic force and polarity of cells from peripheral blood or includes creating density-gradient solutions of cells through centrifugation. Research labs’ urgent demand for readily available cells can be difficult to meet without the use of leukopaks in place of PBMC isolation from whole blood.
Peripheral blood can be isolated into its major blood components through isolation protocols. Whole blood is separated into red blood cells (RBCs), plasma, and human PBMCs. The process of extracting PBMCs—and also washing away the RBC and plasma contamination within the solution—is called PBMC isolation.
PBMC isolation is typically accomplished using venipuncture collection from a donor, or buffy coat preparation from a sample of peripheral blood. Whole blood is the primary source of fresh cells used in a wide range of immunology studies and the methods to extract PBMCs are well-established. PBMCs can also be isolated from leukopaks for higher yield and quality.
Using peripheral blood as a starting material for PBMC extraction is still the most commonly used PBMC isolation practice. This is in part due to the well-established and accessible nature of centrifugation and traditional blood collection methods. Using the buffy coat method, the PBMC-rich sample is separated through a series of centrifugation steps and transferred between columns.
The protocol for separating whole blood into individual cell populations is typically composed of cumbersome density gradient separation phases, which are necessary to deplete RBC and plasma content. These separation steps can sometimes damage the desired cells, thus impacting experiment results.
Therefore, separating individual cell types from whole blood samples is generally challenging to scale. In addition to scaling issues, the use of Ficoll is typically present in lymphocyte isolation, which can be harmful to desired cell populations. Although Ficoll is a reliable solvent for the density of white blood cells and can be utilized to clean up blood solutions, the low viscosity requires many repetitions of the procedure before a suitable sample of white blood cells is accessed. When employed over many repetitions, this innocent gradient becomes hazardous for fragile cell populations.
PBMCs play an essential role in the immune system, as they constantly circulate through the bloodstream looking for infection and preparing to launch a defense response. The majority of an isolated PBMC-enriched sample contains lymphocytes—the most common white blood cell—monocytes, and dendritic cells. This increase in concentration is well suited to researchers who need a large number of white blood cells.
However, many large-scale research projects require a greater concentration of PBMCs than those offered through conventional whole-blood extractions. This is largely due to the unscalable nature of whole blood extraction methods—like buffy coat preparation—and the accompanying stubborn RBC and plasma contamination. To overcome these complications, cell biologists can purchase leukopaks or cryopreserved leukopaks for their PBMC isolations.
Leukopaks are collected through leukapheresis, a specific apheresis technique that involves extracting lymphocytes from peripheral blood and returning red blood cells and plasma to the donor. Once donated, the lymphocyte-rich blood can be further isolated into its cell components, providing a robust starting solution of cells for a higher final yield.
Using a leukopak as the starting material for lymphocyte or PBMC isolation provides a higher final yield of desired cells, ensuring sufficient research material. Due to the nature of leukapheresis, a leukopak solution contains less RBC and plasma contamination than peripheral blood samples, making them easier to process immediately into downstream separation steps without an initial RBC depletion protocol or many repetitions of targeted cell isolation. In addition to a decreased contamination level, leukopaks provide a sample enriched with PBMCs, allowing technicians to collect many more desired cells in a single isolation process.
Leukopaks are available in a variety of customizable solutions. Fresh or frozen, they are gathered from a single donor and eliminate donor-to-donor variability that can skew experimental controls and results.
Chosen for many applications because of their ease of accessibility and increased lymphocyte concentration, leukopaks are valuable in immunology and cell therapy studies. These industries demand a reliable source of white blood cells free of contamination, and leukopaks respond to that demand.
Leukopaks are especially advantageous across large-scale studies requiring a considerable amount of white blood cells or PBMCs from a single donor.
Leukopaks are rich in lymphocytes and PBMCs in much higher concentrations than those found within peripheral blood, making them an ideal starting material for PBMC isolation. In addition to a superior solution, leukapheresis can be performed many times in the span of a year on the same donor, much more often than with traditional blood donation. This increase in supply meets the cell demand of the immunology research community.
Process leukopaks efficiently and reliably into a variety of cell populations with Akadeum microbubbles. Explore our solutions for any of your cell isolation needs and protect fragile fresh cells with the best separation technology available, for humans or mammals.
Thanks to our buoyancy-activated cell separation tools, our innovative approach leaves cells totally untouched by magnetic fields and multiple tube transfers. Check out our leukopak processing resources to learn more about how Akadeum is the best option for PBMC isolation from leukopaks.