Phusion Hot Start Flex DNA Polymerase offers robust, high fidelity performance and room temperature reaction setup. The addition of an aptamer-based inhibitor allows room temperature reaction setup. Phusion Hot Start Flex DNA Polymerase is supplied with standard 5X Phusion HF Buffer, as well as 5X Phusion GC Buffer, which can be used for complex or GC-rich templates. Each of these buffers contains MgCl2 (1.5 mM at the final [1X] reaction concentration). Reactions can also be optimized using the provided DMSO or MgCl2 solutions.