2A Sequences and Polycistronic Vector Design Figure 3. Analysis of EGFP expressing mouse ES cells 24 h post transfection. (A) Comparative analysis was conducted to determine the relationship between the mean EGFP expression per positive cell () and the proportion of cells expressing EGFP (). Data presented as mean 6 SEM from 3 independent experiments. AU = arbitrary units. (B) The relationship between the proportion of cells expressing EGFP and number of genes contained within the constructs. Each point on the graph depicts the mean percentage of EGFP expressing cells transfected by one type of vector. PLOS ONE | www.plosone.org 6 November 2012 | Volume 7 | Issue 11 | e48668