Sections not sticking to slides

[GILLIAN NI BHARLO BOTANY PG]

Hi there!
I hope somebody out there can help me with this one, its driving me 
mad. I am doing in situs with RNA probes on stem disc sections from 
resin-embedded stems. I need to find a way of sticking my sections to 
slides that is RNASE-FREE, does not damage endogenous RNA (ie high 
temperatures are out) and sticks my sections to the slides. So far I 
have tried baking the sections at 37 overnight onto 0.1% poly-l-
lysine coated slides and 1% poly-l-lysine coated. THey wont stick!! 
Any help will be sincerely appreciated. (The detection system is an 
anti-dig horseradish peroxidase coupled antibody binding to the Dig-
11-UTP in the RNA probe, in case thats relevant). Thanks in advance,
Gillian