Problems with expression in E.coli

[Dr. Duncan Clark]

In article <3ABB23C6.C3E0E684 at bbm1.ucm.es>, the eminent Sergio at UCM
wrote
>After
>several months of working with them and sending them from lab to lab, they
>didn't express at all (only the original clones worked).

Not too surprising. That is a good example of why one should always work
from master stocks and not passage cultures repetitively.

> I switched to MBP
>fusion system and expression (and specially solubility) are much better, and
>purification are simpler and needs less whasing steps (and no imidazol to worry
>about).

Same applies as above. Go back to a master -70C stock for every culture
otherwise you will select for the most non-toxic (metabolic load,
lethality or whatever to the cell) variants.

Duncan 
-- 
The problem with being on the cutting edge is that you occasionally get 
sliced from time to time....

Duncan Clark
GeneSys Ltd.
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