US Patent 7150980 Methods for DNA amplification and sequencing

The osmoprotectants proline, 2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine (“THP(B)”, and 2-methyl-4-carboxy-5-hydroxy-3,4,5,6,-tetrahydropyrimidine (“THP(A)”) are capable of increasing the thermal stability of DNA polymerases at elevated temperatures. THP(B) is further effective in lowering the melting temperature of double-stranded DNA. Proline, THP(A) and THP(B) are thus useful in procedures involving melting of double-stranded DNA and/or polymerase-mediated DNA synthesis, such as in primer extension, in PCR (polymerase chain reaction) amplification and in DNA sequencing.