buccal testing (cheek sample), Thats where they use the q-tip and rub it inside your mouth to get some cells from your cheek.

cheek swabs and ammnio (before the baby is born…it sometimes works, sometimes not.)
hair will suffice if there are roots on the hair, if not, it won’t work…the roots are what carries the DNA. You need to look that up where you live…sometimes your state will have a lab that does DNA, but sometimes it’s sent out.

cheek swabs.