FIG. 1.

(A) Time course of Flag-tagged protein expression. Cell lines were washed twice with PBS and diluted into media containing or lacking tetracycline such that plates were nearly confluent on the days indicated. Cells were harvested, cell pellets were extracted, and Western analysis was performed by using an anti-Flag antibody to detect levels of Flag-tagged protein. (B and C) Comparative analysis of Flag-tagged protein levels in each cell line. (B) Total cell extract (10, 20, 40, or 60 μg) from each of the B lines or each of the H lines was used for Western analysis with anti-Flag antibody. (C) Anti-Flag immunoreactivity from 60 μg of H17 and H16 extracts was compared to anti-Flag immunoreactivity from 2.5, 5, 10, 20, 40, or 60 μg of B22 extract.