Figure 1. Determination of the optimal DMSO concentration for cryopreservation of bone marrow cells.

Bone marrow (BM) cells were resuspended in heat-inactivated fetal bovine serum containing 0, 5, 10, 15 or 20% DMSO and then stored in liquid nitrogen for one week. Cells were thawed and counted to estimate the number of BM cells after thawing (white bars) and were then cultivated in bone marrow differentiation media. After 7 days of differentiation, the cultures were washed with ice cold PBS to remove undifferentiated cells and the bone marrow derived macrophages (BMDM) were detached from the plates and counted (black bars). The dotted line represents the initial number of frozen BM cells per aliquot.