Fig. 10. Single chromogen whole-mount staining of ecmAO: lacZ expression in migrating slugs. dimB- and a control (random integrant) strain expressing the ecmAO:lacZ reporter fusion were developed for 24 hours in a slug migration chamber. The slugs were then fixed and stained to detect ß-galactosidase. The staining times were controlled, so as to produce approximately equal intensity staining in the extreme tip of the control and the null mutant. However, the same difference in staining patterns was observed at a variety of staining times up to 30 minutes, at which time the reactions started to plateau.