Jr. Smith et al., APPROACH TO GENOTYPING ERRORS CAUSED BY NONTEMPLATED NUCLEOTIDE ADDITION BY TAQ DNA-POLYMERASE, PCR methods and applications, 5(3), 1995, pp. 312-317
Thermostable DNA polymerases can catalyze nontemplated addition of a n
ucleotide to the 3' end of amplification products. This presents a pot
ential source of error in genotyping studies employing Taq DNA polymer
ase to amplify microsatellite loci. Although the activity is marker sp
ecific, experimental variation is often seen In the degree of modifica
tion. Consequently, for a given microsatellite marker, an allele may b
e inconsistently identified as either the unmodified or modified ampli
fication product. Full automation of high-throughput genotyping has be
en hampered by the need for manual editing of data because of this sou
rce of allele misidentification. In this study we estimate a 1% to 3%
error rate attributable to nontemplated nucleotide addition in the ABI
PRISM genotyping system. We present a PCR-based strategy to minimize
this source of error.