Northerns - cDNA lib. screening.

[VASANTHARAJAN JANAKIRAMAN]

Hi netters,

Iam involved in the characterization of expression of genes, 
coding for phenylpropanoid pathway enzymes in pathogen inoculated system 
- in resistant vs susceptible plants. 
When I did the Northerns 2 of my probes gave very faint signals. Further 
upon a colleague's suggestion I intend to construct a cDNA library and 
screen the lib. with the same probes. 
If the probes gave very faint signals on hybridisation, what may be the 
possibility of picking up positive clones upon screening teh lib. with 
the same probes?
Any suggestions/advice welcome in this regard.
Thanks in advance.
bye
Vasanth.