It’s a plant more commonly associated with lava lamps and Pink Floyd than cutting-edge science. But today, a small Marblehead company plans to post online the hundreds of millions of letters of DNA that make up Cannabis sativa in a first step toward truly understanding and enhancing marijuana’s therapeutic potential.

For years, Kevin McKernan built genome sequencing technologies - powerful tools designed to provide insights into cancer and potential treatments.

But when desperate friends with cancer forwarded studies of medical marijuana’s use, he became intrigued. Earlier this summer, he founded Medicinal Genomics, a small firm that will partner with pharmaceutical companies to explore compounds made by the plant.

It’s not what most people would think - or what most stoners might hope. Medicinal Genomics might, for example, use insights from the plant’s genetic blueprint to create a plant that produces more of certain compounds, such as cannabidiol, which shows promise in early cancer studies - and even look at reducing the amount of THC, which gives the plant its psychoactive effects.

“The genetics were poorly understood,’’ McKernan said.

The company ultimately plans to sequence more than a dozen Cannabis species. This fall, Medicinal Genomics will launch an iPad app providing access to the data.

McKernan acknowledged that by making the information public, someone might try to use the genetic code to brew more potent pot. But not him, he swears. He’s only interested in marijuana for its medicinal value.

“Our goal is to help people,’’ he said.

Carolyn Y. Johnson

© Copyright 2011 Globe Newspaper Company.