Blood products such as Peripheral Blood Mononuclear Cells (PBMCs), Bone Marrow Aspirates (BMAs) and leukocytes provide insightful information for assessing disease and immune states across patients. They are easily accessible, minimally invasive, and provide readouts reflective of other organ states. Although existing methods for isolating these cell types are broadly used across traditional bulk assays, the impact of anticoagulants and isolation methods on single cell assay performance is not fully understood. This Technical Note compares different blood collection tubes and PBMC isolation methods, demonstrating how they can be implemented into single cell workflows.