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Help: how to increase carbon dioxide level ? - (Mar/01/2011 )

Hi all

I'm new at this forum.

For the moment I'm working on Sodalis glossinidius. I'm trying to insert a foreign DNA construct via the lambda-Red recombination system. Unfortunately without any success so far: no colonies on agar plates after transformation. Sodalis grows very slowly under microaerophilic (5% O2; 95% CO2)conditions. I've found out that de CampyGen atmospehere generation system (Oxoid) I use only generates 9 - 13% CO2; far less than the optimal level (95%). This may be the reason why the colonies won't grow. Does anybody know how I can increase the CO2 level?


Many thanks.

-Timasi-

Have you tried a candle jar? Depending on whether it is the microaerophilic or capnophilic characteristics of the organism that control growth this may work.

-Micro-

You could get a CO2 cylinder and an O2 cylinder and a couple of regulators ...

-bob1-

The gas cylinder is the best option.

But if that is not available, how about adding dry ice?

-perneseblue-

Thanks all for the commments!

The problem is that the lab I work in doesn't have CO2/O2 cylinders.
How should the dry ice work?

-Timasi-

Timasi on Wed Mar 2 08:57:42 2011 said:


Thanks all for the commments!

The problem is that the lab I work in doesn't have CO2/O2 cylinders.
How should the dry ice work?

Dry ice = carbon dioxide... its just the solid form.
I think this is the best option for you since you dont have the utilities to use a CO2 cilinder.

-pito-

I assume that you've seen the following paper:

Appl Environ Microbiol. 2011 Mar;77(5):1918-20. Epub 2011 Jan 7.
Lambda Red-Mediated Genetic Modification of the Insect Endosymbiont Sodalis glossinidius.
Pontes MH, Dale C.

Did you contact the authors and ask for advice?

-recombinant-