RT-PCR analysis of GFP mRNA transcripts in splenocytes of the rats from different groups. Following administration of DMH for 21 weeks, the rats were sacrificed and their splenocytes were isolated. Subsequently, the GFP mRNA transcripts in spelnocytes from different groups of rats were elevaluated by RT-PCR. β-actin was used as an internal control. Data shown are representative images from three separate experiments. Lane M, DNA marker; 1, PBS; 2, SL3261; 3, SL3261C; 4, SL3261R; 5, Negative control (RNA without reverse transcription).