(Dan Z. - dan at cubmol.bio.columbia.edu - asks about mutation frequencies
expected in various screens)
After a quite heavy EMS mutagenesis (to 30% survival) I got mutations
in several loci with frequencies between 10E-5 and 10E-4. It varies
a lot from gene to gene; under these condition I would screen something
like 40000 to 100000 colonies.
Fatima Cvrckova, IMP Vienna (fatima at aimp.una.ac.at)