to determine whether there are differences between the u1 , u2 , and u3 small nuclear rna 's of human cancer cells ( hela cells ) and human normal fibroblasts ( imr-90 cells ) , and between these uridine-rich small nuclear rna 's of human and novikoff hepatoma cells , the cells were first incubated in eagle 's medium with [ 32p ] pi to label these rna 's uniformly .
C0016030
fibroblasts
C0007634
cells