Effects of storage conditions of human whole blood on the viability of lymphocytes

PURPOSE: To investigate the optimal storage conditions of human whole blood to retain viability of lymphocytes. MATERIAL AND METHODS: Phytohaemagglutinin (PHA) stimulated and unstimulated human whole blood samples were stored for 48-96 h up to one week at 4 degrees C, 20 degrees C and 37 degrees C and were analysed for apoptosis. After 96 h and one week of storage unstimulated cultures were stimulated to proliferate. These cultures and samples stimulated immediately before storing were incubated at 37 degrees C for 56 h and analysed for mitotic index (MI). RESULTS: Lymphocytes undergo apoptosis during storage and this loss of viability is accelerated by increasing both temperature and storage time. In the presence of PHA, incubation at both 4 degrees C and 20 degrees C for 48 h resulted in low percentages of apoptotic cells and after incubation at 4 degrees C for 96 h the cultures grown for 56 h at 37 degrees C revealed the highest percentage of MI. CONCLUSIONS: The storage conditions affect lymphocytes in terms of both cell viability and proliferation. Storage at 4 degrees C for 96 h in presence of PHA was found optimal.