Enhancer Function of Integrated Alb Reporters Figure 2. Characterization of integrated constructs. A: Chromosomal location of the targeting cassette in HuH7-9. Maps show representative integration of the 1.2-kb plasmid P. Plasmids may integrate in two orientations (O1, O2) between RELN and ORC5, respectively, in the same or opposite direction as transcription of both genes (arrows). PCR using primers R1 and F2 (from LoxP), and F1 and R2 (from flanking chromosomal regions), demonstrated that the integrant ends were intact and determined orientation. B: Representative PCR screening of integrants. O1 amplimersare F1 – R1 (302 bp) and F2 – R2 (599 bp). O2 amplimersare F1 – R2 (347 bp) and F2 – R1 (554 bp). C: Representative maps showing PLoS ONE | www.plosone.org 3 August 2011 | Volume 6 | Issue 8 | e23234