Nucleic acid sample preparation methods and compositions

Abstract

The present invention provides compositions and methods for preparing a nucleic acid library in a multi-purpose buffer (e.g., employing whole genome amplification), where nucleic acid purification is not required between or during steps. In certain embodiments, small amounts of starting nucleic acid (e.g., genomic DNA) are employed and the steps are accomplished in a single container. In some embodiments, the nucleic acid library is subjected to sequencing methodologies or rolling circle amplification.

We claim: 
     
         1 . A method of preparing a nucleic acid library in a multi-purpose buffer, comprising:
 a) combining a nucleic acid sample with a multi-purpose buffer, wherein said multi-purpose buffer comprises dNTPs and primers;   b) contacting said multi-purpose buffer with a plurality of substantially purified enzymes, wherein said enzymes have polymerase activity, kinase activity, and phosphatase activity, and wherein said contacting is under conditions such that amplified nucleic acid is generated;   c) treating said multi-purpose buffer such that sheared amplified nucleic acid is generated;   d) treating said multi-purpose buffer to inactivate said polymerase activity; and   e) contacting said multi-purpose buffer with a ligase and nucleic acid adapters under conditions such that an adapter-linked nucleic acid library is generated;   wherein the above steps are completed in said multi-purpose buffer without nucleic acid purification.