The present invention provides compositions and methods for rapidly amplifying target nucleic acid (e.g., using whole genome amplification) that allows small amounts of starting nucleic acid to be employed. In certain embodiments, the methods employ compositions that comprise: phi29 polymerase, exo− Klenow polymerase and/or Klenow polymerase, dNTPs, primers, and a buffering agent. In some embodiments, the target nucleic acid is amplified at a rate that would result in at least 1000-fold amplification in thirty minutes.