With this test we examine the paternal line to determine whether or not two or more participants share the same biological father.
Determine relationship through the paternal line
A Y chromosome test is used to examine if 2 or more male persons belong to the same paternal line. Men possess one X and one Y chromosome. Their sons will always receive the Y chromosome from their biological fathers. Accordingly, a Y chromosome DNA test establishes a biological relationship between men. Still, this relationship could also mean they are cousins or nephew and uncle, it does not conclusively show they are brothers.
Testing to prove two or more male participants share the same biological father
While a Y chromosome test will establish a relationship through the paternal line this extensive DNA test will provide a likelihood for full, half or no siblingship between males. Such a DNA test is recommendable if there is a risk that 2 male relations may be the biological father.
Searching the biological mother
With a DNA test we can also determine if two males share the same biological mother. The mother's samples are not mandatory for this analysis.