From one of the cases from the WTC, I know that R Elyashiv did not rely on DNA alone to be matir an agunah. And not because he was unaware what DNA is. He paskined that DNA alone is not enough. It was only in conjuction with other proofs that they were able to be matir the agunah.
I heard this directly from a rov who was actively involved in the case. (He was the one who brought the shaila to R Elyashiv on behalf of the Agunah).