Immigration procedures for family reunification in the United States now necessitate the DNA testing of claimants from certain countries in order to establish filiation. Although these tests are not a legal obligation, the immigration service nonetheless regularly requires them for claimants from countries where birth certificates are suspected of being fraudulent. State and personal truths are thus countered by a truth that is al legedly absolute for its neutrality, where biology is turned into an auditing technique. Based on ethnographic fieldwork in a DNA testing center in Brooklyn (New York), this article questions the “geneticization” of immigration’s auditing techniques and its consequences on family and national histories.