Figure 4From: Cloning of transgenic tobacco BY-2 cells; an efficient method to analyse and reduce high natural heterogeneity of transgene expressionFrequency of GFP-expression categories after the cloning of primary and secondary BY-2 lines. (a) Primary cloning of suspensions obtained from calli directly after transformation. (b) Secondary cloning of selected subclones. The cloned lines are on the left, with progenies indicated by letters on the right. GFP-expression categories: ++, strong fluorescence; + weak fluorescence, - no fluorescence.Back to article page