M13: plates are all blue!
MAlexeyev at biost1.thi.tmc.edu
Fri Sep 1 21:14:41 EST 1995
In article <JO_C.6.30463E2D at vcp.monash.edu.au>, JO_C at vcp.monash.edu.au (Jo
> I've just done a M13 transformation and plated out in top agar the lawn
> IPTG, X-gal and the transfored cells. This morning all the plates are a
> lovely shade of blue. The lawn is intact and there are some plaques, but I
> can't tell the color of them because of the blue background.
> Has anyone got any explaination? The same transformation worked last week.
> Could one of the reagants gone off in that time?
You could've gotten a blue lawn if you used by mistake lac+ bacteria, say,
HB101, K802, LE392, etc. (lacY1 mutation does not prevent blue
coloration). If these bacteria (that is often a case) do not have F prime,
they will not give rize to plaques. Just my 2 cents...
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