Lymphocyte subset analysis by flow cytometry. Comparison of three different staining techniques and effects of blood storage.

Flow cytometric analysis enables the researcher and clinician to enumerate lymphocyte subsets in peripheral blood mononuclear cells (PBMC). Often blood samples are collected at one site and then shipped to another site for analysis. Many options in the storage, preparation, and staining of PBMC for flow cytometric analysis exist. Preparation techniques include the conventional Ficoll-Paque (FP) density centrifugation versus the whole blood technique with red blood cells (RBC) lysed using a lysing reagent. In comparing three methods of PBMC preparation, and comparing the staining of fresh blood cells with staining of cells after storage for 24 h at 4 degrees C, analyses show how these different techniques affect the results.