Determination of whether two individuals are half siblings (only one parent in common.)
	Determination of whether two individuals are full siblings (same mother and same father.)
	Method of choice in situations where the parents are unavailable for testing.

To determine whether two children have the same father
The sibship test is often used by mothers to determine whether her children have the same father in situations where the alleged father cannot be tested. If the children have the same mother and same father, the test will show that they are full siblings. If the children have the same mother but different fathers, the test will show that they are half siblings.

To help individuals who have been adopted find their biological families
DNA labs often encounter cases where adults who never knew their family in the past believe to have found their biological families, but the alleged parents are deceased. The sibling test can be used to determine whether they are related to other children of the deceased parents.

To assist in cases where the biological parents cannot be tested
Although the parentage test is the most accurate and recommended method to determine relationships, in many cases, the parents are not available for testing. In such situations, the sibling test may be the best alternative in helping to answer relationship questions. It doesn't matter whether the potential siblings are male or female, they could all be tested against one another to determine whether they are full siblings, half siblings, or not related.