Proper agarose for bacteria colony? - (Jun/07/2015 )

Can I use any ordinary food grade agar for bacterial colonies like e.coli, or do I need some sort of special lab-grade agar?

Sincerely, N00b.

Food grade should be fine.

bob1 on Sun Jun 7 21:03:05 2015 said:

Food grade should be fine.

And this does not matter even if I plan on doing modifications to that very same e.coli, say making vectors?

No it doesn't matter, the agar is just a medium for the bacteria to grow on. The bacteria usually live in an evironment where there are a lot of contaminating DNA and other substances, but still grow happily. Most of the time DNA (which is the one you should be concerned about) is degraded by secreted DNases. To get DNA into E coli, you need to have certain chemical conditions and apply a shock (temperature or electrical) to the membrane that causes holes in it, so that the DNA can enter.

Check out how to prepare chemically competent cells (for heat shock) at http://openwetware.org/wiki/Protocols. I like the Top10 protocol, but the others work well too.

bob1 on Mon Jun 8 02:53:53 2015 said:

No it doesn't matter, the agar is just a medium for the bacteria to grow on. The bacteria usually live in an evironment where there are a lot of contaminating DNA and other substances, but still grow happily. Most of the time DNA (which is the one you should be concerned about) is degraded by secreted DNases. To get DNA into E coli, you need to have certain chemical conditions and apply a shock (temperature or electrical) to the membrane that causes holes in it, so that the DNA can enter.

 

Check out how to prepare chemically competent cells (for heat shock) at http://openwetware.org/wiki/Protocols. I like the Top10 protocol, but the others work well too.

Thanks Bob! This is killer info.