Functional comaparison of PBMCs isolated by Cell Preparation Tubes (CPT) vs Lymphoprep Tubes

Abstract

Background : Cryopreserved human peripheral blood mononuclear cells (PBMCs) are a commonly used sample type for a variety of immunological assays. Many factors can affect the quality of PBMCs, and careful consideration and validation of an appropriate PBMC isolation and cryopreservation method is important for well-designed clinical studies. A major point of divergence in PBMC isolation protocols is the collection of blood, either directly into vacutainers pre-filled with density gradient medium or the use of conical tubes containing a porous barrier to separate the density gradient medium from blood. Results : To address potential differences in sample outcome, we isolated, cryopreserved, and compared frequency and functionality of PBMCs using parallel protocols differing only in the use of one of two common tube types for isolation. Whole blood was processed in parallel using both Cell Preparation Tubesä (CPT, BD Biosciences) and Lymphoprepä Tubes (Axis-Shield) and assessed for yield and viability prior to cryopreservation. After thawing, samples were further examined by flow cytometry for cell yield, cell viability, frequency of ten cell subsets, and capacity for stimulation-dependent CD4+ and CD8+ T cell intracellular cytokine production. Cell recovery, viability, frequency of immune cell subsets, and T cell functionality between PBMC samples isolated using CPT or Lymphoprep tubes were comparable. Conclusion : CPT and Lymphoprep tubes are both effective for PBMC isolation and may be used interchangeably for immunological studies involving T cell activation.