Ecoli contamination in Abgrobact.culture

[Fejes ErzsThetabet]

Dear Immo,
     Please check the ketolactose test in Hooykaas, P.Mol.Biol.Manual
A4:1-13 (1988) (Kluwer, Dordrecht). Original paper: Nature 197 (1963)
406-407. You have to grow your suspectedly contaminated bacteria
on a lactose plate (go for single colonies):
     1% lactose
     0.1% yeast extract
     2% Difco agar

You prepare Benedict's reagent:
     for 1 l of reagent, dissolve
         13.2 g CuSO4x5H2O
         256 g Na2CO3x10H2O or 94,87 g Na2CO3
         132 g Na3-citrate or 150.4 g Na2-citratex2H2O

When the bacterial colonies are fully grown, pour enough reagent on
the plate to cover the plate. Agrobacterium colonies will develop a
yellow zone around the colony. Biotype I Agrobacteria (which include
e.g. C58) give this reaction.

With best regards,
Zso Fejes


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