ST. LOUIS — Growing up, Khrys Vaughan always believed that she had inherited her looks and mannerisms from her father, and that her appreciation for tradition and old-fashioned gentility stemmed from her parents’ Southern roots. But those facets of her self-image crumbled when she was told, at age 42, that she had been adopted.

She began searching for her origins, only to find out that her adoption records had been sealed, a common practice in the 1960s. Then Mrs. Vaughan stumbled across an ad from a DNA testing company offering to help people who had been adopted find clues to their ancestry and connections to blood relatives.

About five weeks after shipping off two tiny vials of her cells from a swab of her cheek, Mrs. Vaughan received an e-mail informing her that her bloodlines extended to France, Romania and West Africa. She was also given the names and e-mail addresses of a dozen distant cousins. This month, she drove 208 miles from her hometown here to Evansville, Ind., to meet her third cousin, the first relative to respond to her e-mails. Mrs. Vaughan is black and her cousin is white, and they have yet to find their common ancestor. But Mrs. Vaughan says that does not matter.

“Somebody is related to me in this world,” she said. “Somebody out there has my blood. I can look at her and say, ‘This is my family.’ ”