Flow cytometry analysis was performed to analyse the composition of isolated lymphocytes.  Lymphocytes were obtained below leukocytes and were gated to identify the cells. B cells separated from blood of patients and cultured in L15 medium with and without bacteria were used. This study was performed at the Department of Immunology, University hospital of Linköping by staff using the same established method to identify the leukocytes in patients. Few samples (n=3) were analysed and therefore the analysis for significance was not performed. The cells were identified by their cell surface proteins. B cells were CD3- and CD19+ while T cells were CD3+ and CD19-. Plasma cells were in different stage of maturation and some cell surface proteins were not specified. But the CD3- cells that were larger in size and were not identified to be B or T cells were identified as mature B cells (ie. plasma cells).