Hello, I am interested in starting a project to localize a single
copy gene on maize, corn, meiotic pachytene chromosomes. We have
localized a repetative sequence with FISH and now want to see if we
can detect a single copy gene. I have heard that really large probes
are needed and that the probe can not contain any repetative element
in an intron or spacer region that will light up other sequences in
the genome. I am also curious about the type of probe synthesized. I
have seen people use nested sets of random oligo labelled probes
thinking that the small probes will hyb first and that the longer
probes would have a overhanging tail which then would hybridize to
other labelled strands creating a tree of probe at the site. Sounds
complicated. In situ PCR may be useful to generate signal too but I
have no experience with this. We have been using DIG labelled RNA
probes. Thanks for the help in advance, Lorraine
