In article <CBCrG9.9nI at ccu.umanitoba.ca>, browns at ccu.umanitoba.ca (Stuart Brown) writes:
> I have had mixed success with the Invitrogen kit. The secret seems to
> be choosing the right colonies off of your kanamycin plate. Not the
> white ones, not the blue ones, but the sort of whitish ones with tiny
> blue dots in the center. I don't know why this is, but there is some
> mumbling in the kit's instructions about out of frame religation of the
> vector forming white "background" colonies.
Sounds like you're getting light-blue colonies. Maybe your insert has an
initiation codon and it lacks in-frame termination codon ?
Sometimes you get false positive LB-colonies, if there has been a base pair
deletion during the linearization/religation step.
Jari Louhelainen
University of Helsinki
Department of General Microbiology
FINLAND
