Intracellular antigen investigations by means of flow cytometry are essential for immune phenotypical studies of oncohematological diseases. The use of Saponin for cellular permeabilization has proved to be cost-effective. Due to its detergent properties, Saponin permeabilizes the cytoplasmatic membrane without harming it or altering membrane antigen expressions, thus allowing simultaneous detection of intracellular and surface antigens. The objective was to analyze the efficiency of the cell permeabilization technique using Saponin as a permeabilizing agent. Thirty-six samples of peripheral blood and bone marrow underwent an immune phenotypical study at the Immune Pathology Laboratory of the Hospital das Clínicas of the University of São Paulo. Direct immunofluorescence was accomplished using the CellQuest program (Becton Dickinson, San Jose, CA) of the FACSCalibur flow cytometer (Becton Dickinson, San Jose, CA) to acquire and analyze the data. Excessive cell loss was observed when using rinsing buffers stored for more than seven days at temperatures ranging from 2ºC to 8ºC. Minimal cell loss was found when rinsing buffers were used immediately after preparation or frozen at the time of preparation and thawed just before use. In order to eliminate excessive cell loss, a systematic analysis of the technique stages was carried out, allowing us to restructure the technique to our purposes and its use in our laboratory. In a country with scarce resources, a viable, faster, more cost-effective technique (35% reduction in cost) aimed at investigating intracellular antigens by flow cytometry has been standardized.
Flow cytometry; cytoplasmatic membrane; saponin; cellular permeabilization; intracellular antigens
