Can the paternity test of half-brothers be found out?

Paternity tests can be done between brothers, whether they are half-brothers or half-brothers.

The identification between brothers is generally by detecting the Y chromosome STR of the identified person. The inheritance of Y chromosome follows the law of paternal inheritance, which can only be passed from grandfather to father and uncle to their son. So as long as they are the same grandfather, their Y chromosome typing will be the same. If you want to confirm whether it is a brotherly relationship, you can test whether the Y chromosomes of the identified people are consistent. As long as their performances are the same, it means that there is a brotherly relationship.

However, if the appraiser wants to identify whether he is a half-brother and has a mother sample, he can compare the two samples with his mother to verify whether there is a mother-child relationship. If they are born to the same mother, you can confirm the existence of brotherhood. It can also detect the mitochondria of the identified person, because the inheritance of mitochondria follows the maternal inheritance law, and their mitochondrial dna is the same as long as they are born by the same mother.