oligos vs others

[Barney P. Crum]

I'm currently doing northerns using a 35mer oligo to probe for a specific
RNA sequence.  I am having trouble getting the necessary signal generated
and was wondering if other probes may work better for Northern hybridization
(i.e. a larger probe or RNA probe).  I know that the mRNA is in high enough
abundance to detect it using in situ hybridization.  Any ideas will greatly
help.  Thanks.