Effect of antisense construct on endogenous Ptpγ expression. RT-PCR products from untransfected cells (lane 1), cells transfected with the antisense construct B (lane 2), and transfected with empty vector (lane 3); plasmid indicates the murine Ptpγ cDNA cloned in the Bluescript SK-vector and used as a control for the size of the expected PCR product and the success of the reaction. Actin indicates the amplification of the 209-bp product derived from murine actin mRNA. 3404F/3856R and 2993F/2075R indicate the sequence numbers of the first nucleotide amplified by the specific 5′ primer (F ) and the sequence number of the last 3′ nucleotide (R). Next to the open arrow is the size of the amplified product. The PCR reaction was performed for a longer number of cycles (35) then the samples in Fig 1, to detect minute amounts of transcripts.