Figure 1. CLL cells co-cultured on stromal cells demonstrate time-dependent sustainability (A-I).

CLL lymphocytes were incubated with NKTert stromal cell line at different time periods (1–6 days) and the viability of cells was measured by Annexin V/PI staining (A–F). Mean % survival of CLL lymphocytes was compared between suspension cultures and stroma co-cultures using Annexin V staining method (G) and DiOC₆ staining method (H). The ‘d’ denotes ‘day’. Values obtained from two standard methods for same patient samples were correlated (Annexin V and DiOC₆) to obtain a linear correlation (I). Paired student t-tests (two tailed) statistical analysis was performed (*P<0.05, **P<0.01, ***P<0.001, ****P<0.0001).