Fig. 5.

Fraction of mutant APC gene fragments in the plasma of patients with various colorectal tumors [adenomas (Ad) and Dukes' stage A, B, and D carcinomas]. In each mutation analyzed, DNA from normal lymphoid cells or plasma DNA from healthy donors was used as a control (Normal). The “mutants” observed in assays with normal cellular DNA represent errors generated during the PCR process rather than mutations present in the template DNA (see text). The red lines represent the mean, minimum, and maximum values of the normal controls.