The Native Environment (NE) proliferation assays are performed for those compounds in which cell cycle arrest is suspected to be more relevant than depletion. The drug effect is measured on both the proliferating and nonproliferating cell subsets. For cell proliferation analysis, CFDA staining in conjunction with the immunophenotype allow the analysis of both viability (Annexin-V negative) and proliferation (CFDA peaks) of the blast cells.

To more closely reproduce and re-create the complexity of the in vivo microenvironment in CLL, we have developed an ex vivo assay that best promotes CLL proliferation and viability with the combination of CpG + IL-2 + HS5 stromal cells, that approximates a lymph node environment. Human stromal cel lines have been reported to prevent spontaneous death and promote proliferation of tumor cells.

To more closely reproduce and re-create the complexity of the in vivo microenvironment in MM, we have developed an ex vivo assay that best promotes MM proliferation and viability adding in the cell culture medium autologous or heterologous reconcentrated plasma. With this assay we prevent spontaneous death and promote proliferation of tumor cells.