Figure 2: Characterization of MSCs cultured under different conditions. (a) Schematic diagram representing the three initial cell culture conditions. (b) Morphological appearance of MSCs under the three different culture conditions. Scale bar: 200 μm. (c) Approximate number of MSCs cultured under the three different conditions at the time of harvest. (d) Hierarchical clustering analysis of differentially expressed genes. MSCs at passage 2 were used for microarray analysis. Each row represents a single gene, while each column represents the gene expression levels for each individual culture condition ( independent samples for each culture condition analyzed). The color corresponding to the level of gene expression varies from red for the lowest level of expression to green for the highest level of expression.