One student’s DNA — when it showed up in a test tube — resembled an ornate letter “H.” As Ryan Sheeder, the owner of the DNA, carefully examined his very personal genetic sample, biology teacher Renne Lietz was surprised by the design. “Oh, my goodness!” she said.

Sheeder and 65 advanced biology students at Davenport West High School took part this week in three DNA classes taught by guest educator Mike Zeller, the outreach coordinator for Iowa State University’s biotechnology program.

Zeller visited Davenport on Monday to show students how to extract their own DNA and explained how DNA analysis is handled by federal agencies and other organizations.

It’s a lot like what happens on the hit CBS television series “NCIS,” he said, noting that his favorite character on this program is Abby Sciuto, an off-the-wall lab assistant played by actress Pauley Perrette.

DNA applications

Working with DNA is commonly done for forensics purposes, but there’s an emphasis at Iowa State on DNA in agriculture. Lietz is beginning a DNA unit in her biology classes and believes that knowledge of the genetic material helps West students understand how biology works in today’s society.

Zeller told the students that biosciences and genetics are growing job fields and highly paid professions. Some people think of DNA extraction as the domain of the police, FBI and the military, but it has many uses beyond forensics.

Human beings are 99.9 percent similar to each other, and that one-tenth of 1 percent difference is the focus of the DNA test, the scientist said. The most common genetic test today is done on newborn babies for diseases and conditions that include hearing loss, sickle cell anemia and cystic fibrosis.

DNA tests also are being done, to an increasing extent, to determine one’s proclivity for certain diseases. “We can’t cure genetic disease,” Zeller said. “we can only treat it.”

One example is a DNA test for coronary heart disease. A person could discover that they are likely to get the disease and then they could make lifestyle choices to lessen its effect. That individual, however, eventually would die of heart disease, Zeller said.

Swish and spit

The students in Lietz’s morning class filled their mouths with distilled water. They swished it around for a minute and then expelled the contents into a paper cup.

“I do not want to see this!” junior Ciara Severson said. “It’s disgusting,” agreed Breanna Aguirre, a senior.

The actual DNA was affected by the composition of a student’s mouth, which varies in terms of acid content. It also is impacted by food particles left in the mouth.

The teens next pulled some of the water/mouth mixture into a test tube and mixed it with a salt/soap solution. They gently rotated the combination in their hands, warming it a bit with their body heat. Next, they applied ethanol and held the test tubes steady.

The DNA slowly developed before their eyes. Some, like Sheeder’s, came to resemble a tiny statue. Others’ DNA grouped in a thick layer.

“Animal DNA is beautiful, and easy to extract,” Zeller commented, contrasting it with plant DNA, which is difficult to handle.

The West students used a device called a pipettor in the process of translating the extracted DNA. They took a sterile plunger to the DNA, combined it with a colored agent and placed a tiny bit in a gel box. The box was then set on a device and charged with electrical currents.

Over a few hours, the genetic sequencing pattern that results may be printed out for comparison purposes. That, essentially, is how various tests — to determine a child’s paternity or to match suspects to a crime — are done.

“The tests are a little different from each other, but it’s the same techniques at work,” Zeller said.

Keep it forever

A person’s DNA may be kept indefinitely. In a slideshow, Zeller showed how some people translate their DNA to framed art on a bedroom wall. Others keep the actual DNA in alcohol and use the container as jewelry.

West’s students put their DNA samples in small vials full of alcohol. They used a device like a toothpick to extract their DNA from the test tube and transfer it to the vial, closing it so it could be taken home.

Many teens enjoyed the DNA demonstration. “I thought it was pretty cool,” Sheeder said. “It was very interesting actually. I’ve never done this before.”

“It was pretty interesting and fun, too,” agreed Matt McCune, Sheeder’s lab partner.

Time in the class went quickly for Alejandra Calzada, a senior. “It made science really feel like science,” she said.

Lietz has taught biology for 20 years, six at West High. She first learned about the biotechnology presentation at the Iowa Science Teachers convention and also took a summer workshop on the topic.

The teacher was happy with the way her students responded to their visitor. “They were involved once it got rolling,” she said. “The students were very engaged.”