Miklós Kásler - Zoltán Szentirmay (szerk.): Identifying the Árpád Dynasty Skeletons Interred in the Matthias Church. Applying data from historical, archaeological, anthropological, radiological, morphological, radiocarbon dating and genetic research (Budapest, 2021)
CHAPTER SEVEN – Genetic investigations
(a) for the most part, the extent of the DNA templates degradation, (b) the PCR circumstances and the Taq polymerase used, (c) it is more common in the case of longer alleles, within the given marker, and (d) further unique characteristics of the marker. Non-template addition Taq polymerase often adds an extra nucleotide to the end of a PCR product, mostly an adenine (called “adenilation”). In the case of partial adenylation some of the PCR products do not have the extra adenine (-A peaks), other products do (+A peaks). All of this results in the peak becoming broader (in the case of poor resolution), or in the case of good resolution, a split peak can be seen. In the case of several samples, variation in the adenylation status affected the markers length and genotype. For example, the 12 allele of the non-adenylated D2S441 marker is the same length as the completely adenylated D2S441 11.3 allele, as both contain the same number of repeating microsatellite units, and base number variation only exists within one repeating unit. The same applies, for example, to alleles TH01 10 and TH01 9.3. Therefore, it is important to amplify purely +A or -A samples instead of investigating +/- mixed samples (Butler 2012). Several methods exist for the pure +A or -A conversion of samples, but we did not perform these. Microvariant and “off-ladder” alleles Human populations may contain DNA markers which differ from common STR allele variants by one or more basepairs. Differences 126
