Walt's world

Professor is using $1m grant to encourage student scientific research

A sheepish smile flits across the lips of the professor in the gray tweed coat as he recounts a lab experiment conducted during his first college summer:

He had been trying for days to work the kinks out of an organic chemistry procedure. Problem was, he hadn't yet learned organic chemistry. So, instead of the brown powder he was hoping for, the untried lab assistant kept getting a tarry, black gunk.

And then, one day, it happened - a beautiful brown substance formed at the bottom of the glass bottle. The student immediately held the vessel up to show his teacher. That's when smoke began curling out of the bottle, and the professor yelled, "Drop it and run!"

The brown powder burned a hole in the ceiling. The bottle melted into the floor.

"I shouldn't have exposed it to air without quenching it with water [to stop the chemical reaction]," 55-year-old David R. Walt acknowledges all these years later, eyes twinkling. "But I was just a curious freshman who wanted to show his professor."

And the result of that long-ago explosion? Well, Walt - who now teaches organic chemistry at Tufts University - is lounging on a couch at a hotel in Copley Square, chatting about the $1 million Howard Hughes Medical Institute grant he's using to bring real-world research opportunities to high school and college students.

No accident, that. There are no such things in Walt's world, which is ruled by the serendipity of science (aka, the idea that great discoveries often occur through happenstance or luck).

Already, several Malden High biology teachers have used Walt's instructions to help their classes collect saliva samples and analyze their mitochondrial DNA - which is passed from mother to child - for certain genes.

That's going way beyond squinting through a microscope at somebody's cheek cells, says Malden High chemistry teacher Diane Perito, who helped her colleagues conduct the experiment with their classes earlier this school year.

"You could see the strands of DNA . . . in their solutions," said Perito, a Tufts alum who once studied under Walt. "This took it [a typical science experiment] another step and made it, 'Wow, I hear all about this, I hear all about the human genome, but until you tell me it's real, until you make it real . . . it's just another thing I have to learn.' "

Walt is trying to foster just that kind of excitement. He is one of seven New England professors - five are in Massachusetts - with projects currently being funded by the Howard Hughes Medical Institute, says Peter Bruns, vice president of the institute's grants program. Professors, he adds, are chosen because they have "interesting ideas in science education" that will inspire the next generation of scientists.

Walt, who lives in the Back Bay, explains his take on the situation: "Today, the conventional way of teaching is you stand up and lecture . . . you pass out problem sets. The difference is that's not really the way we do science."

In the real world, science is trial and error, Walt says. It's asking questions that don't have set answers. What it's not is the "cookbook chemistry" students commonly learn in high school where, as Walt puts it, "you're following a recipe and if you do everything the book says, you'll get the product you're supposed to . . . like baking cookies or making a cake."

He wants students to have the same live-and-learn experience he did as a freshman.

So, for the past two years, Walt has used his million working with undergraduate and graduate and postdoctoral students to simplify and refine experiments that could soon be used to help young scientists create and test different strains of penicillin, or to track their DNA through the human genome and research their genealogy.

Recent Malden High graduate Varandt Khodaverdian spent last summer working in Walt's world - a sunlit, third-floor lab in the Pearson building at Tufts University. He will return there tomorrow for another stint.

"At first it was overwhelming," recalled Khodaverdian, who recently finished his freshman year in college.

He made flashcards to help himself learn the science lingo and concepts he heard other researchers using. "It's very different, because in high school you do experiments that you know what the outcome should be, and they've been done a thousand times. But in Professor Walt's lab, you're doing experiments that maybe haven't been done."

Despite all the research being conducted on a recent Tuesday, things are pretty quiet in the lab.

Student researchers sit at computer terminals - many plugged into their iPods - as they examine test results. Raghnild Dragoy Whitaker, a chemistry PhD student, pauses in a back room while trying to explain how the honey-colored, toothpick-sized fiber she's holding is actually a bundle of thousands that is embedded with DNA. Nearby is a glass slide - a DNA microarray - that contains a bunch of tiny holes filled with DNA beads.

A few minutes later, Walt uses a snippet of purple latex glove to demonstrate the workings of a fluorescent minimicroscope his students built out of PVC pipe, lenses, and an AA-battery-powered green LED. The $200 contraption - nicknamed "The Ray" - resembles a large T-shaped inhaler, but does the same thing as the $250,000 machine in another room: compares DNA from a saliva sample with a synthetic sample contained on a microarray.

Whenever DNA on the saliva sample matches the synthetic stuff, it will light up like a little neon sign.

"Here, try it," he says, positioning the ray over the purple latex. "If you look in here, the LED is actually illuminating a square."

His excitement is infectious as he explains what he hopes will eventually happen with the ray: "High school kids, they're going to build it . . . the students build that, they make their own arrays, then they do their own testing."

Sometimes those tests will work, he says. And sometimes they won't. But, after all, that's the way science happens in the real world.