Figure 2.
Mutational spectra of lung, colon, and muscle samples. DNA was isolated from ≈1 g of epithelial cells from a human colon, 1 g of human muscle tissue, and two samples of 106 human bronchial epithelial cells each. DNA was restriction digested and mixed with internal standards, and the mutational spectra were determined. Depicted are separations of fluorescein-labeled samples along with the coseparated tetramethylrhodamine-labeled authentic standards (lower of each pair of curves) for samples of two lungs, colon, and muscle. The x and y axes and labels are as in Fig. 1. “X” marks a peak that has not yet been sequenced.