ATLANTA (AP) _ Every day, Luanne Elliott dons a 10-pound spacesuit, hooks up her oxygen and enters a heavily guarded laboratory to do battle with a new virus that has killed 24 people.

About 19,000 samples later, she finally has the first significant breakthrough: She got the hantavirus to grow in two generations of laboratory mice.

That's the first step in isolating a virus, and it came none too soon for the frustrated virologist with the Centers for Disease Control and Prevention.

''I was almost to the point where I might have slit my wrists if they didn't have some good results,'' Ms. Elliott said. ''I didn't know it was this hard, I really didn't.''

A never-before-seen strain of hantavirus has turned the lungs of at least 40 people in 11 states to soup, killing 24 of them.

Hantavirus causes kidney disease in Asia, but the organism had never been found in the Western Hemisphere until there was an outbreak in the Southwest in May.

It is spread by close contact with rodents and their droppings. Baffled doctors can only advise people to stay away from deer mice that may carry it. Only when the CDC isolates the virus in its lab will scientists learn enough about it to work on treatments.

On Tuesday, after five months of analyzing samples of blood and tissue from rodents and hantavirus victims, the CDC finally had some progress to report when Ms. Elliott got the virus to infect the two generations of mice.

Now she must get the same virus to grow in test tubes - outside a living creature - so scientists can learn how it works.

They'll also use it to make tests to determine if people have hantavirus, which begins by mimicking the flu.

Because it has taken so long to isolate the virus, the CDC and the University of New Mexico are preparing a molecular-engineered protein from the virus to use as a test. It may be available within weeks, but one made from the actual virus would work better.

That still may be months away, Ms. Elliott said. Hantavirus is notorious for resisting scientists. The first strain ever isolated took five years.

It is tedious work in the most heavily guarded lab in the bowels of CDC, tedious even for someone who has spent almost 20 years fighting the world's deadliest viruses.

Little metal canisters containing blood and tissue are flown in every day from around the country. Researchers pluck them from a huge cardboard box and do sophisticated molecular tests to determine which contain measurable amounts of virus. So far, about 19,000 have been tested.

Ms. Elliott took 100 of the best samples into her lab to try to grow them.

Because the virus is so deadly, she puts on a protective spacesuit and passes through a submarine-like air hatch into a Defense Department-designed lab. There, she inoculates mice with hantavirus-infected cells and tries to get some of those same cells to grow in tissue cultures in test tubes.

Along the way, she discovered that the genetic makeup of the virus is slightly different in victims from different states - proof that hantavirus has lurked undetected in this country for years, evolving to adapt to different climates.

But she still doesn't know why the virus suddenly began infecting people, or what else she could do to speed up her efforts to isolate it.

''It just keeps happening, people die so quickly, and we won't be able to help until we get it isolated,'' Ms. Elliott said in frustration. ''They say dumb persistence is what paid off in the past.''