Help with calling a public method from masterpage

I have created a Web User Control with a public method. I created a masterpage and declared a public method in codebehind which is calling the public method in my WUC. I add a Master Directive to the ASPX page i.e. 
MasterType VirtualPath="/myMaster.master" In codebehind on this ASPX page i try and access the public method delcared in the masterpage:
Master.
but the puclic method is not listed there. How should i be accessing the public method?
Thanks