In Reply: Drs Lorenzen and Willerslev are incorrect regarding insufficient contamination prevention and quality control measures during our study. In addition, authentic, adequately preserved DNA can indeed be obtained from Egyptian mummy tissue (Figure 1) but requires specifically adapted extraction protocols.
The following aspects substantiate authenticity. (1) All generally accepted criteria for ancient DNA authentication1,2 were strictly adhered to before, during, and after genetic analysis experiments, as described in our article. (2) Putative contamination by people handling the mummies before the sampling and during the experiments was monitored. (3) All female mummies were negative for Y-chromosomal markers. (4) All male mummies showed homozygous (ie, hemizygous) Y-chromosomal profiles. (5) The profiles and haplotypes of the whole set of mummies showed individual differences and therefore could not have originated from the same source of putative contaminant DNA. (6) The combination of nuclear data (Y- and autosomal chromosome–related markers) complemented each other. (7) Reproducible genotypes were obtained from different biopsies and extractions per mummy. (8) Subsets of the data were independently replicated in a second, separate ancient DNA laboratory staffed by a separate group of personnel, who reconfirmed the authenticity of the results. (9) DNA isolated from Egyptian mummies was highly informative when processed with next generation sequencing.
Gad YZ, Selim A, Pusch CM. King Tutankhamun’s Family and Demise—Reply. JAMA. 2010;303(24):2471-2475. doi:10.1001/jama.2010.823