The enhancement of homogenous mass extension reaction: Comparison of two enzymes

Reliable and efficient PCR and extension reactions using standardized procedures are key elements for successful single nucleotide polymorphism (SNP) genotyping projects. To improve the cost efficiency and overall performance of SNP genotyping we evaluated two commercial thermostable DNA polymerases used for the extension reaction in the homogeneous mass extension MassARRAY genotyping system. The aim was to study whether the quality, accuracy, and expenses of a new TERMIPol® DNA polymerase are competitive to the commonly used ThermoSequenase® DNA polymerase. We compared the enzymes by testing 96 SNPs genotyped for DNA samples of 31 unrelated individuals and one water control. The success rates, congruence between the genotypes and completeness of extension reactions support the use of TERMIPol®, especially when the amplification of the higher mass allele is difficult. Further, using TERMIPol® enabled successful genotyping (>93%) of several SNPs that failed (<80% success) when using ThermoSequenase®.