Semiquantitative RT-PCR analysis of GM-CSF transcript levels. (A) Autoradiogram showing incorporated radioactivity of amplification products obtained from PV PBMNCs cultured in suspension with or without IL-10 for 48 hours. (B) Autoradiogram showing ABL transcripts that served as a reference to correct for potential variations of RNA or cDNA samples. (C) Corrected GM-CSF transcript levels in cultured PV cells. Each sample was analyzed in three radioactive PCR analyses in duplicate using freshly synthesized cDNA. The quantity of ³²P incorporated into PCR product was determined by densitometric scanning of the autoradiograms. Results were corrected by dividing GM-CSF values by the mean values obtained from six ABL transcripts of that cDNA. The results are shown as mean values.