GUS staining

[HEAZLEWOOD,Joshua]

In <3cnh98$qdk at mark.ucdavis.edu> ez005679 at dale.ucdavis.edu writes:

> Hi, everyone:
> 	I have a little problem in gus staining.   What I did is staining 
> the young tomato leaf/cotyledon with GUS ( 5mg X-gluc disolved into 200ul 
> Dimethylformamide, add into 5ml 50mM phosphate solultion, vacuum for 
> 20 min, stain at 37dgree C for 16hrs.).   My problem is the 
> leaf/cotyledons are not stained uniformly.  While some specks/areas are 
> heavyly stained, other part are not blue at all.   
> 	I wonder if anybody can nicely give me any suggestions to improve 
> my staining.   If you have any successful experience, PLEASE HELP.
> 
> 	Thanks in advance.
> 
> 		Yusen Tong

Try using 20% methanol in your X-gluc solution, vacuum, and incubate as above.
The methanol seems to allow penetration of the substrate into the tissue far
more readily, as you would expect. See Plant Science 70 1990 133-140.
Originally used to suppress putative endogenous GUS activity.

Josh