By Ben Gruber

PALO ALTO (Reuters) - Playing classic video games like Pac-Man with living single-celled microbes thinner than a human hair is now possible thanks to an interactive microscope developed by bioengineers at Stanford University.

After several prototypes, the researchers released blueprints earlier this month for a "LudusScope" in the international scientific journal PLOS ONE, offering kids of all ages a playful window into the world of microbiology.

“It’s a microscope that you can 3D print and build yourself,” Ingmar Riedel-Kruse, an assistant professor of bioengineering at Stanford, told Reuters.

After it is assembled, tiny, light-responsive organisms called Euglena swim on a microscope slide surrounded by four LED lights. The lights are controlled by a joystick, allowing users to control the direction in which the microbes move.

“You turn microscopy from something that is purely observational into something that is interactive,” Riedel-Kruse said.

The final component is a smartphone that attaches to the eyepiece of the device, transforming it from a simple interactive microscope into a rudimentary gaming platform and research tool.

The scientists at the Palo Alto-based university have developed software programs that overlay on top of the image of cells. By selecting specific cells, users can influence their movement and guide them through a maze that resembles the 1980s video game Pac-Man. Kids can also play soccer by steering their microbes through goal posts.

The games, according to Riedel-Kruse, evolve into basic research.

“You can select a cell, track it and collect data about it that you can then analyze and discuss," Riedel-Kruse said. "You can really do simple research in educational settings.”

Using the plans publicly published, anyone can build a LudusScope now, but Riedel-Kruse said assembly is complex.

He plans to use recently awarded grant money to further develop the microscope into a ready-to-use science kit that he hopes will be commercially available in 2018.

(Reporting by Ben Gruber in Palo Alto; Editing by Melissa Fares and Frances Kerry)