FIG. 1.

DNA-PKcs is undetectable in slip mice. (a) Whole-cell extracts (200 μg) prepared from the thymuses and colons of FVB/N and slip mice were analyzed for the presence of DNA-PKcs (460 kDa) by Western blotting. Equal loading of protein in each lane was determined by using Ponceau S staining of the nitrocellulose membrane prior to antibody incubation (data not shown). (b) Whole-cell extracts of FVB/N, scid, and slip MEFs were used to confirm that slip mice lack any detectable levels of DNA-PKcs, which is present in both FVB/N and scid cells. Here, equal loading of protein extracts was monitored by antiactin antibody detection.