How to prepare Gram(+) bacteria for electrotransformation - (Feb/13/2012 )

I would use untransformed cells to test the MIC, then use about 3x MIC in plates for selection. MIC is easy to measure. Infect media with your culture, then aliquot 100 ul into a row of wells on a plate. Add antibiotic to media at a high known concentration, then add 100 ul to the leftmost well. Do 2x serial dilutions across the row, leaving the last well untouched (zero antibiotic). Cover, incubate, and observe growth.