Detection of iNOS mRNA in livers of mice injected with d-GalN and LPS. iNOS mRNA products of 807 bp were obtained after amplification using total RNA from mice injected with PBS (lanes 2 and 3), d-GalN (lanes 4 and 5), LPS (lanes 6 and 7), or d-GalN and LPS (lanes 8 and 9). Lane 1, DNA size marker; lanes 2 to 9, mRNA products of iNOS (lanes 3, 5, 7, and 9) and the housekeeping gene GAPDH (lanes 2, 4, 6, and 8). The arrow indicates the size of the expected amplification product of the mRNA for iNOS.