DNA testing is the process of taking the father’s blood and matching it with the blood of his children. For human development, half of the chromosomes are from the paternal line and half are from the maternal line. In the case of biological children, the number of chromosomes and the degree of similarity need to be proportional. If the paternity test reveals that the DNA similarity is low, it is mostly considered not to be a biological child; if the DNA is rechecked and the DNA similarity is high, it is mostly considered to be a biological child. Therefore, for DNA comparison, mainly to identify whether it is a biological son as well as daughter, such identification has the influence of technical factors, so it is recommended to go to a professional institution for DNA comparison check.