How may I relinquish the right to make a claim against the estate of my deceased putative father?

I am seeking to determine if a now deceased man was my biological father. His children are willing to assist by taking a DNA test, however they are concerned about possible legal liabilities that may arise if the paternity is confirmed. My sole interest is to determine if this man was my father, thus I think I need to make a legally binding contract or declaration that relinquishes any possible claim I might make against the decedent's estate, widow and/or children. My putative father was a resident of New Jersey at the time of his death. Additional details of possible relevance: I was born in New York 61 years ago, was later adopted by another man in New Jersey, and presently reside in Washington State.