Copy number control using temperature

An overnight culture of pHIND2.2 was grown at 30°C. Dilutions of this culture were made into fresh media and grown overnight(18 hours) at the specified temperatures. 4 O.D. of each culture was harvested and lysed using lysozyme, SDS, and heat. Samples were then treated with RNAse and analyzed on an agarose gel. Each lane contains the equivalent of 0.08 O.D. of culture. Using the chromosomal DNA as an internal standard one can see an increase in the copy number of the plasmid when grown at elevated temperature.