Making ampicillin plates from plain LB plates - Making amp plates from prepoured LB plates (Dec/21/2005 )

Hi,
Does anyone know how i can make up some ampicillin plates from already poured pure LB plates? I was told something along the lines of: add about 330 microliters LB + 100microgram/ml AMP to plate then let dry for about 20min. Then, i can add my transformation mix. Does this method sound correct?
Thanks all,
C

Yes, that's about right. Our stock ampicillin is stored at 100 mg/ml in 50% EtOH, which we dilute 1000x for broth and plates. A plate has about 25 ml of agar medium, so it needs about 25 ul of the ampicilliin stock solution. This is a little tough to spread uniformly, so you'd really like about another 100ul of water to help with that. To do this, your plates need to be a little on the dry side. Best results if the plates can sit for an hour or so before use to allow the ampicillin to diffuse.

Thank you, your response was helpful