Can you do a paternity test with siblings?

Answer 1

Yes. You can determine paternity from DNA samples of siblings. This is done by using the gel electrophoresis method. Based upon the bands which are seen, one can denote the paternity as well as maternity. But for this the DNA sample of the father/s is also tested.

This method is frequently used in Forensic Science.

Answer 2

While the most accurate results are achieved with samples from the alleged father, the child, and the mother, there are other ways to get results.

In the case where the alleged father will not, or cannot, consent to the test, a sample can be used from a relative of the alleged father. The important bit of DNA from the father is also present in the father's relatives. Note that without the father's sample the test result in this case may be less accurate.

Similarly, the test can be performed with just the alleged father and child samples as well. However, it's always best to submit samples from the alleged father, the child, and the mother in order to get the most accurate results.