cDNA libraries

[Robert B. Darnell]

In article <01H99ALNX69G8WWD9O at MGRP.BGSM.WFU.EDU> ,
BOWDEN at MGRP.BGSM.WFU.EDU writes:
>	One of my colleuges, who is not on the net, is trying to clone the
>human gene for which they have pcr'ed an exon. The problem is they are
not
>certain where it might be. They have hints from rat: pancreas, brain,
heart,
>and kidney; more or less in that order. Does anyone have human cDNA
libraries...

What about a little characterization of the presumptive exon, before
obtaining and screening a shotgun of cDNA libraries.  Northern blots
across species at low stringency is an obvious first shot (?hinted at in
your post); these could be followed up by RT-PCR with cloning and
sequencing of your PCR products as a straightforward way to confirm the
expression and obtain a species specific probe for further
characterization.  Finally, if you find it absolutely necessary to
analyse human mRNA, Clontech sells a premade "multiple tissue Northern
blot" made from human mRNA (I have no affiliation with them, but have
found analysis of human mRNA by Northern a tough proposition due to poor
quality of the tissues).