bubbles in LB plates - (Nov/30/2004 )

Hi All,

I have a problem with my LB plates. Soon after I put them at 37 (like in 1hr), there seem to appear many small bubbles in the agar. After overnight incubation, the bubbles are still there and are increased in numbers. In doesnt affect E. Coli growth, but it doesnt feel right either. Maybe something is wrong with the LB medium? Any ideas.

Thanks a lot,

Tau

hi

try to maintain ur LB agar media at 45 C before u pour the plates. even if the agar is not melted properly u can get such bubbles'
regards
madhan

Hi

In my experience, we can see lots of air bubbles in LB plates only when stored at 4 C for long periods, and brought to 37 C incubator.
To avoid bublles we can incubate upright for 1-2 h at 37 C and can be inverted.

In my consideration freshly prepared plates should not bubble up at any time. If its so, please do melt the LB agar in microwave not more than 2 min time. over heating of agar also will reault in bubble formation.

also, there is another reason like when you have LB agar in a conical flask which has been melted earlier to prepare plates and the left out LB agar when you reheat you will get bubbles.

Best wishes,
ravi
INDIA

We are having this problem also. A person in the media room makes them for us and I can not pin point what he is doing. It doesn't happen all the time. The plates are fine at 4oc and stored inverted, but when they are warmed up to 37oC, bubbles occur. If the plates are warmed first to RT, then put at 37oC, there are not as many bubbles as if go directly to 37oC. With the bubbles it is hard to pick clones.

Thanks for the ideas.

I have also noticed that when the plates are left upright for 30-60min at RT and then 30min at 37 before plating, there seem to be lesser numberof plates! with bubbles. The conc of bubbles dont change however. Either have of dont.

It is interesting how some plates get bubbles and other, made with the same LB , dont. But since it doesnt affect E.Coli growth,... Indeed however, it is more difficult to pick colonies from bubble-infested plates.

Good luck and regards to all,

Tau