Anyone who has ever idly popped a sheet of Bubble Wrap should feel a little sheepish, considering the humanitarian breakthrough that Matthew Huber, 13, achieved with the same irresistible stuff.

Matthew, a seventh-grader in St. Peter, Minn., won the grand prize in last weekend's fourth annual Bubble Wrap Competition for Young Inventors, a national contest that attracted more than 2,500 entries among students in grades 5-8. He used large Bubble Wrap to make "Petri Bubbles," an inexpensive alternative to Petri dishes.

"You take Bubble Wrap and then just put it in this stand and cut the tops off the bubbles," he said in a telephone interview.

The shallow "dishes" then can be filled with agar, in which microorganisms can be cultured.

"It's a lot better than normal Petri dishes because it costs a lot less to transport to emergencies," he said. Judges from the Sealed Air Corp., creator of the wrap, noted his invention can be used in remote areas far from hospitals or labs to verify the safety of drinking water.

Necessity, as usual, was the mother of this invention. "I was doing this science experiment where I needed Petri dishes, but I only had two of them so I had to think of alternatives," Matthew said. He was one of three finalists flown to New York City to demonstrate his invention. For his efforts, he earned a $10,000 savings bond, and St. Peter Middle School also gets $5,000.

Matthew is the son of Tom and Marlys Huber.