FIG. 2.

DNA degradation and PARP-1 cleavage in MNV-1-infected RAW264.7 cells. The results of isolation of total DNA and gel electrophoresis of DNA fragments over time are shown. Data represent mock-infected RAW264.7 cells (28 h p.i.; lane 1), MNV-1-infected RAW264.7 cells harvested at 4, 8, 12, 16, 20, 24, and 28 h p.i. (lanes 2 to 8), and a DNA marker (M; lane 9). An aliquot of the harvested cells was subjected to electrophoresis in an acrylamide gel and then transferred to a nitrocellulose membrane. Cleaved PARP-1 was detected in all samples (except for the samples from 28 h p.i., which were not tested) with a mouse antibody specific for the 89-kDa cleavage product.