RT-PCR for transcription of genes. A) Agarose gel electrophoresis analysis of RT-PCR amplicons. Lane 1, DNA marker; lane 2, cells transfected with pEGFP-N1; 3, cell transfected with pEGFP-N1-DTA; expression of DTA was seen only in the second group, and not in the first. Actb was used as an internal control. B) Western blot analysis of cell extracts using anti-GFP and anti-β-actin antibodies. Lane 1, control group transfected with pEGFP-N1; lane 2, experimental group transfected with pEGFP-N1-DTA. EGFP protein was detected in control group, and the DTA-EGFP fusion protein in experimental group. The expression level of DTA-EGFP fusion protein was lower than EGFP, and the expression of β-actin in experimental group was less than that in control group.