Description

About Our Donors

Our healthy human peripheral blood mononuclear cells (PBMCs) are sourced from a renowned world-class blood collection center that has been a pioneer in many screening processes. All donors have been tested for various infectious diseases, including HIV and Hepatitis B/C, as well as normal levels of hemoglobin. Further, donors undergo a screening questionnaire to disclose vital statistics, medication, cancer history, and travel history to ensure that they are healthy and their PBMCs will reliably serve your research endeavors.

About Human PBMCs

Human PBMCs are cells isolated from the peripheral blood of human donors. They are specifically isolated by performing a density centrifugation at room temperature under sterile conditions to remove red blood cells. This process leaves a mixture of cells that comprise mostly of white blood cells that include T cells, B cells, NK cells, and monocytes, which can be used in a variety of immunology-based applications.

Because of the cell populations found in PBMCs, they are widely used by scientists for the study of immunology, infectious diseases, cancer, and autoimmunity. In addition, certain subsets of cells in the PBMCs can be isolated to perform experiments with the specific goal of interrogating the role of that distinct population in a certain experimental context.

Application Summary for Human Irradiated PBMCs

Human irradiated PBMCs are commonly used as antigen presenting cells, stimulation/feeder cells, or target cells in a wide variety of immunology-based applications. Unlike unirradiated cells, these cells will not divide or respond to stimulus. However, the antigen presenting cells found in the peripheral blood, such as dendritic cells, macrophages, and B cells, can still present antigenic peptide to stimulate exogenously added CD4 and CD8 T cells in which their TCR recognizes the peptide. In these types of co-culture studies that require antigen presentation, peptide is added to the irradiated cells, which then present the peptide to activate T cells in order to produce cytokines, proliferate, and perform cytotoxicity.

Irradiated PBMCs can also be used as stimulator cells in mixed lymphocyte reactions (MLR). In this type of experiment, the irradiated cells and exogenously added effector cells, which are typically T cells, are of different genetic backgrounds. In particular, they are of different MHC haplotypes. The effector cells will respond to the difference in the MHC haplotype and begin to produce cytokines, proliferate, and perform cytotoxicity.

Isolation of PBMCs

Peripheral blood is obtained from responsible facilities that have many years of experience collecting samples. Since the facilities are local, the blood is quickly transported to iQ Biosciences’ laboratory for processing.

Once at our lab, PBMCs are isolated by performing density centrifugation with Ficoll, a high molecular weight sucrose solution, to remove red blood cells under sterile conditions. Depending on the species (human or non-human) of blood, either 1.077 or 1.084 g/ml Ficoll is used, resulting in a perfect layer of mononuclear cells that are separated from plasma, platelets, granulocytes, and erythrocytes. Additional quality control steps are taken to isolate and prepare PBMCs that ensure the highest viability for cryopreservation and downstream experimental applications.

Irradiation of PBMCs

After isolation of PBMCs, the cells are irradiated using X-ray radiation at a dosage that stops cell division, but permits retention of cellular processes, including antigen processing and presentation.

Cryopreservation and Storage

Our human irradiated PBMCs are cryopreserved carefully using iQ Biosciences’ cryopreservation protocol that ensures high viability (> 80%) after thawing.

Cells should be stored at < -120°C once they are received, such as within a liquid nitrogen tank (vapor phase).

Quality Control Process

We implement random sampling per lot to test for viability and cell counts to ensure they meet specifications, which are recorded on the Certificate of Analysis that is included with each shipment. Cell counts are obtained using a manual hemocytometer and then cross-referenced with an automated cell counter. Each lot is also characterized for unique cell populations by immunophenotyping, in which the results are also recorded on the Certificate of Analysis.