If it is any conciliation I am having a bad day also !

I have spent months trying to isolate a mutant yeast allele that causes a phenotype that I can see.

I finally got back a plasmid only to discover that it has no mutations in it.

This means that I either have not rescued the right allele or the phenotype is due to a mutation in a gene I don't care about.

Both are bad !

bugger !