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Image: HVS

An immunofluorescence image of a human mesenchymal stem cell growing on a plate of microposts, which have the approximate consistency of Silly Putty. This image was taken after one day of culturing. The red dots are the microposts, which are relatively short in this sample. The green is the cell and the blue is its nucleus. This cell will differentiate into a bone cell.

Image: HVS

An image taken with a scanning electron microscope of a human mesenchymal stem cell growing on a plate of long microposts approximately 13 microns in length. After one day of culturing, this cell exerts centripetal force, which can be seen in the bending of the microposts. This cell will differentiate into a fat cell.

Image: HVS

An image taken with a scanning electron microscope of human mesenchymal stem cells growing on a plate of short microposts. After one day of culturing, these cells spread more than cells cultured on long microposts. These will differentiate into bone cells. Even though these cells bend their shorter microposts less than their counterparts growing on longer microposts, they exert greater force to do so.

Image: HVS

An image taken with a scanning electron microscope of a human mesenchymal stem cell growing on a plate of long microposts, which can be seen bending in response to the cell's forces. This will become a fat cell. The stem cells round up on taller and softer microposts and differentiate into fat cells. They spread out on the shorter and stiffer substrates and become bone cells.