molecular biology techniques are widely used in genotyping applications and other areas such as biological research , forensic and diagnostic applications , including human identification and paternity testing and for diagnosis of infectious diseases or chimera analysis after allogeneic bone marrow transplantation as well the detection of genetic diseases and cancer . the most commonly used technique is the polymerase chain reaction that allows the researchers to amplify the desired dna requiring only tiny amounts of sample . such amplification reactions are technically challenging and are often hampered by several practical issues such as the presence of pcr inhibitors , sample degradation and low quantities of said sample . the invention addresses these issues by means of an internal amplification control consisting of a set of primers and an artificial template . the primers define two fragments of different sizes . the examples show that this system allows the researcher to distinguish between the presence of inhibitors and sample degradation .