Fig. 1

Set-up of the experiment. The study was performed on six transfected clones. Before the stability study began, all six of these clones were grown with MTX in the media to enhance the productivity of the clones. At the beginning of the study, all of the six clones were split and further grown without and with MTX in the media. ‘Beginning’ refers to the beginning of the stability study (sampling at weeks 1, 2) and contains data from the six clones grown without and with MTX in the media, giving 24 samples. Similarly, 24 samples were collected in weeks 9 and 10, and are referred to as the ‘End’ samples