If the child shows alleles that are not identified with the alleged father during the examination, then the possibility of paternity is completely ruled out (100%). Suppose during the examination the child shows alleles that are identical to those of the father. In that case, the probability of paternity is calculated mathematically based on the frequency of these alleles in the general population and is considered practically proven when it exceeds 99.99%.
For a DNA paternity test to be considered valid, it must include the analysis of at least 16 internationally recognized genetic markers. In cases where identification is observed between the father and the child, the identification should be accompanied by the probability of paternity which should exceed 99.99%.

Rates lower than this are an indication and not proof of paternity. The use of internationally recognized methodologies allows the results to be repeated and verified in any laboratory in the world.Only from a genetic fingerprint is it possible to conclude whether two or more persons are siblings, half-siblings, or whether there is no blood relationship between them. A prerequisite for this is the analysis of the DNA of the individuals involved. If there is an uncle, mother or aunt, the result of the sibling test becomes even more accurate.
Depending on the configuration of the family tree and the range of the test, we can arrive at values greater than 99.0% for a complex blood affinity test. The nature of the index plays no role in whether siblings belong to the male or female sex.In case the person to be examined belongs to the male sex, we can examine additional parental information with the help of the Y chromosome marker and come to very accurate results regarding the degree of blood kinship. A son always has the same Y chromosome profile as his father/grandfather; even two brothers have the same Y profile. The maternal lines can be determined by mtDNA. Sons and daughters have the mother's mtDNA.