LYNNWOOD — Through plastic safety glasses, Kevin Lo, 12, stared into a vial containing cloudy liquid — what started out as a mouthful of his own spit — and a small mass of strange, white tendrils, twisting and spiraling upward from the murk.

“It looks like an alien planet,” Kevin said.

In fact, it was his own DNA.

The sixth-grader at Martha Lake Elementary School was among the first wave of students to be paid a visit from the Science Adventure Lab, a custom-built 45-foot bus equipped by Seattle Children’s Research Institute.

Students from various classes at the school earlier this month got to use micropipettes, heat blocks, reagents and other tools of the medical trade to isolate DNA from their cheek cells, among other lessons.

“This is not Playskool science,” said Dr. Amanda Jones, a microbiologist with the Research Institute who heads the Science Adventure Lab program and leads the classes. “This looks just like one of the labs in our research institute. It’s the same stuff that I have in my lab.”

That includes the hot pink and fluorescent orange test tube racks. (“Scientists love colors,” Jones said.)

The mobile lab was the brainchild of Dr. James B. Hendricks, president of Seattle Children’s Research Institute, according to Jones. Hendricks headed a similar effort, with a vaccination bus, in New Orleans.

Such mobile science labs are a growing trend. The Seattle bus is the latest in a fleet of about 20 nationwide, according to the Mobile Laboratory Coalition in Boston.

Seattle Children’s bus is the first on the West Coast, organizers say, and is the only mobile lab connected to a children’s hospital.

Teachers and principals requested visits ahead of time, and slots filled quickly. The lab will have taught more than 1,000 school children by the end of this month alone. The calendar also includes a stop in December at Briercrest Elementary School in Shoreline. In all, the bus is scheduled to visit 5,000 kids from 200 classes statewide in its inaugural school year.

“People are seeing that it’s more cost effective in the long run to put together these mobile labs,” Jones said.

Most schools don’t have the resources to upgrade their science equipment, and the mobile lab allows students to do experiments “that they otherwise wouldn’t have had the opportunity to do,” Jones said.

“We hope they see science is fun and achievable — something they can do, that it’s not something only a few select people understand but that is a part of everybody’s life,” she said.

The mobile lab targets students in the fourth through eighth grades with medical, health and nutrition topics. Besides the class on understanding and isolating DNA, the lab also includes lessons on chemistry, DNA fingerprinting and understanding respiratory function. Students use gel electrophoresis, perform biochemical assays and measure heart rates with pulse oximeters.

By getting young children to perform real science experiments, the hope is that more kids will see science careers as a goal — or at least be less intimidated as they face more advanced topics in high school and college.

“Kids have a natural curiosity, and you just need to cultivate that,” Jones said.

“There’s also the ‘wow’ factor,” she added.

And there were plenty of “wows,” “whoas” and, of course, “ewws” at last week’s DNA class.

As with any serious endeavor aimed at tweens, the class came with some unusual rules.

“Don’t shake the tube. You’ll hurt your DNA,” and, “You do not get to drink it. This is a science lab.”

It also came with creative definitions for complicated terms. Take lysis, for instance, the process of dissolving cells. “How about we blow them up?” Jones asked the students, to smiles.

Yet the class also sparked wide-eyed discussion.

“Is cloning — can you actually do it? Can you make a copy of a person?” wondered Dong Kim, 11.

The students bubbled with excitement as they left the bus, parked between the playground and the school, to file back to class.

“It was really fun when we got to see our DNA floating around in a tube,” said Kateka Seth, 11, who wants to be a surgeon when she grows up.

The lesson also fueled Amina Donahoe’s interest in science. “When you’re actually doing the experiments, it feels different,” the 11-year-old said.