Is it permissible, Islamically, to conduct DNA testing on children when there is suspicion regarding the wife, and is this test considered an accusation of unchastity even if done secretly?

Qadhf (calumny) is explicitly or implicitly accusing others of adultery, and it is forbidden and one of the seven destructive sins. Testing with the wife's consent is not considered qadhf, and it is impermissible to accuse one's wife of adultery unless there is certainty as clear as day. As for someone other than the spouse, four witnesses are required; otherwise, the accuser is a liar and a transgressor and shall be flogged eighty lashes, and he will be subject to curses and a great torment. One should not undertake this test because it does not yield any شرعية (Islamically lawful) benefit and because it is a cause for whispers (waswas) and doubts.