Dvorak heads a team of 12 scientists and technicians who are working with embryonic stem cells from mice and humans. Dvorak slips a white lab coat over his "United States of America" T-shirt before opening the door to a tiny room off a main hallway.
It's in this sterile lab where human embryonic stem cells -- which are susceptible to contamination -- are being cultured in what Dvorak describes as a "restricted zone."
"So this is our best-developed facility," Dvorak said. "So we have these doors, and inside there is HEPA (High Efficiency Particulate Air) filtration, three levels of HEPA filtration -- very clean air. This is our good-quality facility. Of course, the other institutes probably have bigger labs and more labs, but this quite enough for us."
The trim 49-year-old Dvorak and his team made international headlines when, in 2003, they isolated a new line of human embryonic stem cells, or ESLs. Many laboratories have tried to derive human ESLs, but only a handful have succeeded.
Dvorak said his lab -- part of the Institute of Experimental Medicine at the Czech Academy of Sciences -- was only the second to do so in Europe, after a facility in Sweden. A U.S. laboratory was the first, in 1998.
Peter Andrews, a professor of biomedical science at Sheffield University in England and one of the world's leading researchers in the field, described Dvorak as a dedicated scientist who -- along with his colleague, Ales Hampl -- are providing an important part of the stem-cell "jigsaw puzzle," all on a shoestring budget.
"In the Czech Republic, the resources are probably rather less than many of us have elsewhere," Andrews said. "That they can achieve some of these things is really quite impressive."
While acknowledging funding challenges, Dvorak bristles at suggestions his laboratory is second-rate. He's visited stem-cell labs from the United States to Japan, and said his compares favorably.
He smiled when asked to explain his work in simple language. It's not an easy task.
Stem cells, he said, fall into two basic types. The first is somatic stem cells, which give rise only to cells specific to the source from which they were harvested.
"The other stem cells are embryonic stem cells, which are derived from early-stage embryos several days old -- in the case of humans, it's 5 1/2 days, six days old -- where in the embryos exist a small group of cells which is really universal," Dvorak said. "We call them totipotent. And these cells can be maintained in such status, such universal status, and also under certain conditions can give rise to all cells of the body."
Couples from a nearby in-vitro fertilization clinic donate surplus human embryos to the Brno lab. But the procedure has sparked an ethical debate, since the embryos must be destroyed to reap the stem cells.
The issue has led the administration of U.S. President George W. Bush to withhold all government funding for new human stem-cell research.
Dvorak said he believes this is misguided. Like many others, he is convinced stem-cell therapy may one day be used to treat, or even cure, degenerative neurological illnesses such as Parkinson's or Alzheimer's.
"The first argument to derive human embryonic stem cells is this great future with human cell therapy," Dvorak said. "We can rescue a lot of patients, can help them to live, can improve the treatment for thousands and thousands of seriously damaged patients. So I think that's a great future. And nobody can say that it is more ethical to let the leftover embryos [be stored] in liquid nitrogen with no future, than to derive cell lines to help people."
Dvorak was excited as he explained his laboratory's latest discovery -- a possible mechanism to keep human stem cells in their original "blank" state. The leading international scientific journal in the field, "Stem Cells," is about to publish a paper detailing the findings.
"It's not the biggest deal to derive embryonic stem cells from human embryos because this is just the start of very hard work. And everybody who derived embryonic stem cells from human embryos knows that the harder time will come," Dvorak said. "We did some experiments also with our cells, and we think that we have discovered some critical mechanism which can be involved in maintaining the cell type in undifferentiated status -- in the status when the cells are really totipotent."
Professor Andrews in Sheffield said Dvorak's latest work is vital if the promise of stem cells is to be realized.
"I know one specific area that [Dvorak] is interested in is the role of a particular growth factor called FGF in controlling the behavior of embryonic stem cells," Andrews said. "And this is a sort of fundamental area for us. Embryonic stem cells do a couple of things. One, they will differentiate into all sort of cell types, and that's what excites everyone, because we can turn them, hopefully, in the long run, into cells that can be used for therapeutic purposes. But the problem is they do that when they feel like it, and we need to be able to control that."
There were fears Dvorak's lab might have to close last year due to funding problems. But the concerns were premature.
The lab will be receiving about 200,000 euros ($261,000) every 18 months for the next five years, courtesy of the European Commission. It is also now receiving about 2 million crowns a year ($86,800) from the Czech Grant Agency in Prague.
Later this summer, the entire laboratory will be moving into new facilities at Masaryk University in Brno. And the Czech parliament is soon expected to pass a bill setting guidelines on the use of human ESLs. Dvorak says the bill will have a "very positive" impact on research.
Dvorak said the future for his work is looking, as he puts it, "quite nice."