balb/c mouse macrophage problem - (Jan/21/2007 )

Has anyone grow RAW 264.7 balb/c mice macrophage cells before? I got them from ATCC and i had some problem with my cells. When i recieve the cells from ATCC, they are all right - I mean that the cells still viable. However, after i grow them in a flask, i noticed that they grow very slow. From the picture of the cell line showed on ATCC weibsite, the cells can grow very close to each other when it is confluent and there are 'arms'-like thing which reach out from the cells. (http://www.atcc.org/common/images/Cells/TIB-71_mg1.jpg).
My cells do not look like that at all. no matter how frequent i change the media to make sure it has enough nutrition; or no matter how long i try to grow it in flask, it still look pitiful... the cells scattered here and there, far from each other, no 'arm'-like thing. It never confluent. However, it still viable.
I can't figure out what happen. can anyone help???

May be you are subculturing the cells in low density and the cells may not like it...
...try culture them in higher density by plating them in a smaller flask or 6 well plate.

Hope this may help.