Generation and characterization of the knockdown efficiency of bic155, a mammalian expression vector encoding miR-155. A, Schematic diagrams to show bic155(top), a construct containing nucleotides 134-283 of exon 3 of the bic gene, and GFP/miR-155as (bottom), a reporter construct containing a sequence perfectly antisense to miR-155 in the 3' UTR of GFP. B, Fluorescence microscope image at 24 hrs of DC-1 cells transfected with GFP/miR-155as in combination with either bic155(panel I) or a control construct encoding non-specific miRNA (panel II). GFP/miR-155as and bic155transfection complexes were formulated in Lipofectamine 2000 in a 1:9 mass ratio. The knockdown efficiency of bic155was measured as the relative difference in fluorescent intensity between the two groups. For further characterization of bic155, DC-1 cells were also transfected with GFP/control (panel III), GFP/control and bic155(panel IV), or GFP/miR-155 (panel V).