The effect of Ca-formaldehyde fixation on the activity of the reporter enzyme beta-glucuronidase (GUS) in transgenic tobacco.

The inhibition of beta-glucuronidase (GUS) activity by Ca-formaldehyde fixation was investigated in leaves of transgenic tobacco (Nicotiana tabacum L.) expressing the beta-glucuronidase uidA reporter gene from Escherichia coli. One-hour fixation of a free-floating leaf disc in a cold fixative decreased the activity of GUS by 60% as compared with the untreated control disc kept in a moist chamber.