Changes in gene expression after storage in liquid nitrogen. The changes in gene expression after thawing the cells and culturing for up to six passages were compared with the freshly cultured cells with passage 1 as baseline for the comparison. The blue regression line shows the values for passage 2 to 6 after thawing of the cells when compared with passage 1 of the freshly cultured cells, including passage 2 (blue square). The red regression line shows the values for the passages 3 to 6 without the first passage after thawing of the cells (excluding the value in the blue square), showing that the passage immediately after thawing showes higher values of differentially expressed genes due to the thawing procedure. p, passage.
Neumann et al. Arthritis Research & Therapy 2010 12:R83 doi:10.1186/ar3010