using a vector lab MOM kit on mouse antibody on mouse tissue

 HI 
I am trying to do a very basic islet1 antibody staining on mouse tissue (mouse brain and spinal cord). I am getting a very high background with couple of protocols i tried, now i am going to use vector lab MOM kit. I tried it once and i am getting a green background with no specific signal ...  
does anyone have any input on this...? i was using alexa488 and monoclonal islet1 antibody. Eventually i will be using two different antibodies on mouse hindbrain. If i could get some suggestions about fixation, that will be great too,
Thanks a lot 
Aana