Medical testsI?

Question

My Grandfathers father left him when he was a child and i believe he had children with another women.These Children and their children are alive.Is there a medical test that could be given to see if they are blood related to me?Or is it to far down the blood line for a Medical test to tell?If so what type of test is this that i need?

Answer 1

DNA testing would reveal if people are related, i.e. have a common ancestor.