GUS staining protocol

• Cut off primary inflorescences and transfer to a microfuge tube.
• Fill the tube with the GUS staining solution but leave tops of tubes uncapped.
• To remove air trapped in the inflorescenes, place the tubes in bench top aspriator and pull a vacuum for 5 min or longer, release vacuum and repeat. Be sure that the flowers are completely submerged in the solution.
• Cap the tubes and incubate at 37šC with agitation for about 48 hours.
• Remove the stain solution and replace with 70% EtOH.
• Change the 70% EtOH twice over a 24 hour period until chlorophyll is removed from flowers and the blue GUS stain is clearly visible.

GUS staining solution

• 50mM NaHPO4 - pH 7.2
• 0.5% Triton X-100
• 1mM X-Gluc (diluted from a 20mM stock made up in dimethylformamide)
• We buy our X-gluc from Rose Scientific.