Fig. 2. Total and K-ras p21-GTP in E10 and E9 cells during culture growth and confluence. Separate assay blots for E10 and E9 cells are shown. A, total K-ras p21 increased in E10 cells during culture growth, with relative scan values of 142, 379, 388, and 670 at 50, 70, 100, and 100% 2 days postconfluence (Lanes 14). In E9 cells, total K-ras p21 was relatively high at lower confluencies; relative scan values were 784, 668, 1012, and 1467 (Lanes 58). B, active K-ras p21-GTP also increased markedly during the growth of the E10 cultures and was especially high at postconfluence (100%, Day 3); relative scan values were 47, 204, 352, and 951 (Lanes 14). An increase in K-ras p21-GTP also occurred with culture density in the E9 cells; relative scan values were 207, 489, 1314, and 1434 (Lanes 58).