Please use spermidine at room temperature

 Spermidine is a compound that is used as an enhancer of T7 RNA polymerase activity when we synthesize artificial RNA in vitro. Although the principal mechanism of spermidine for this purpose is unclear, it has been exploited by molecular biologists for several decades. Spermidine has an characteristic that precipitates DNA in the low temperature, which may cause a problem because we use DNA as a template for T7 polymerase. If we prepare the reaction buffer on ice, the template DNA may be inactive due to the property of spermidine. Therefore you should prepare it at room temperature, and then please start the reaction at 37°C.