My name is Fei Wang at the university of Minnesota. Recently, I have been
working on screening a tomato (Lycopersicon esculentum cv VF36) genomic library
using a tomato cDNA clone as the probe to pull the corresponding genomic clone.
However, after screening about one million plaques, I still have not found any
positive clones.
I have checked my screening technique by screening a cDNA library in parallell
using the same probe. IUve got many positive cDNA clones from the cDNA
library. From this I concluded that my lifting, transfering and the probe were
OK.
From what I can think of, the problems could arise from the following:
a. I have not screened enough plaques and need to just continue to screen.
Howeg th one million plaques should give 99% chance of getting the clone.
b. The genomic library I am screening is not representative of the tomato
genome. The genemic library was constructed by cloning Sau3A digesed tomato DNA
into lEMB1 victor in 1987. Currently, the titer has dropped to 1* 10 5 pfu/ul.
I would appreciate any comments on the above situation.
**** I am interested in obtaining another tomato genomic library to screen. If
anyone has such a library or knows of someone who would be willing to share one
please let me know by email. ********
Fei Wang
fwang at molbio.cbs.umn.edu
