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The initial study of ancient DNA (aDNA) dates back to the year 1984 when a scientist named Russ Higuchi and his colleagues separately described DNA sequences from a type of zebra (quagga) and an ancient Egyptian individual that were 150 and 2400 year old specimens respectively. aDNA research is generally defined as the recovery of DNA sequences from museum specimens, archaeological discoveries, remains of the fossil and various unusual sources. The study of aDNA became possible with the invention of techniques that amplify specific DNA sequences with the aid of enzymes. At present the reports of analysed specimens that are hundreds, thousands, and also millions of years old are almost considered a routine.
The authenticity of ancient DNA (aDNA) is based on the following considerations:

• Examination of the associated remains that whether it is well preserved equally or do they show any evidence of contamination. Biochemical preservation of the specimen, which includes the preservation of other biomolecules that associate with the survival of the DNA, for instance, collagen or amino-acid racemisation (AAR), must indicate excellent sample preservation.

• Work areas must be isolated in order to separate samples and extracted DNA from PCR amplified products. Screening for the various contaminants that enter at any stage of the process is necessary and can be achieved by negative extraction control and amplification.

• The successful amplification of large fragments of the ancient DNA should be carried out with caution owing to DNA degradation.

• The reproducibility of the result is of utmost importance and should produce consistent results each and every time such as with polymerase chain reaction and extractions.

• Cloning of products is essential in order to access for contamination, damage and with jumping PCR (A method for reconstruction and replication of doubled stranded DNA that is randomly damaged, for instance, damaged DNA often found in mummified tissues or museum specimens).

• The results that are generated by carrying out the same experiment by various independent research groups should be consistent.

• Quantification is carried out by competitive PCR or Real-Time PCR to provide an indication of the initial number of templates in the reaction.