The FBI has begun looking for a 22-year-old laboratory technician who vanished Saturday from her office at a National Institutes of Health research lab in Frederick County.

Corinne Elise Cavalier of Brunswick, Md., a technician at the NIH's Frederick Cancer Research Facility at Fort Detrick, was last seen in the facility about 10 a.m. Saturday, FBI spokesman James Dearborn said. Agents searching for Cavalier found her keys and purse in her office and located her car in its usual parking area outside the facility, he said.

Cavalier, who was scheduled to attend a job-related seminar Saturday morning at Hood College in Frederick, left home about 8:30 a.m., but drove to the facility instead, NIH spokesman Francis X. Mahaney said. He said Cavalier entered the building at 9:08 a.m., using her card-key.

The Army conducts biological and chemical weapons research at Fort Detrick, but Mahaney said the NIH lab "is not on the military side of the base" and "is not connected in any way with the U.S. Army." Dearborn said the FBI entered the case because Cavalier was on federal property when she disappeared.

Mahaney said Cavalier, who graduated from Hood College last year with a degree in biology and was living with her parents, attended the first session of the seminar Friday and afterward ate pizza with colleagues. They became concerned over her whereabouts Saturday morning when she failed to appear for the seminar's second session, Mahaney said.

Dearborn said there was no sign of a struggle in her office.

Cavalier is an employee of Program Resources Inc. of Frederick, which operates the facility under a contract with NIH, according to Mahaney.