As applications for the 2012 Inc. 500|5000 arrive, we thought it would be worthwhile to shine a spotlight on some of the companies that are vying to appear on our ranking of the fastest-growing private companies in the U.S. (For more information and to apply, go to here.) One that caught our eye was Englewood, Colorad-based Hands-On Labs.

News of ambitious online distance learning initiatives has dominated headlines recently. But years before professors and entrepreneurs began offering Stanford and MIT courses for free online, Linda Jeschofnig was promoting distance learning, albeit offline.

Since 2000, Jeschofnig’s Hands-On Labs has been selling LabPaqs, science kits that allow high school and college students to conduct experiments and receive course credit from home. And in recent years, the company has more than doubled its revenue from $2.3 million in 2008 to $5.5 million in 2011.

Jeschofnig’s idea for LabPaqs began in 1993 when her husband Peter was working as a chemistry professor at Colorado Mountain College. He was approached by the school to teach a distance learning chemistry course via video, but wanted a way for students to be able to carry out the experiments themselves rather than just watch him.

“We firmly believe in the importance of doing science to learn science and the necessity of tactile experimentation,” Jeschofnig says.

So she, a former CPA, took her husband’s courses, familiarized herself with the field, and began devising a product that enabled safe, hands-on experimentation from remote locations.

The first product, called a Chem Kit, was rolled out in 1994 and was so successful that Linda says students who used it learned more than those in traditional classroom settings.

“When a student is doing their lab work at home, they have to do every step of every lab themselves,” she says. “It’s not a passive experience. Our students tend to do a bit better than those who are taking their labs on campus.”

As distance learning grew during the late ’90s, the Jeschofnigs used their connections in the education sector to make kits specialized to other science disciplines. And in 2000, she turned her products into Hands-On Labs, a business she ran singlehandedly from home.

Sending hazardous materials like hydrochloric acid and cobalt nitrate made finding a manufacturer and liability insurance difficult. But once those obstacles were overcome, Hands-On Labs underwent explosive year-to-year growth selling mixable chemicals and dissectible animal eyes.

In 2002, Hands-On Labs had $8,600 in sales. Two years later, that number had risen to $316,000. By 2005, sales nearly doubled to $600,000.

The company grew so quickly that Linda was forced to retire from teaching business in 2005 so she could devoted herself to the company full-time. The following year her company recorded more than $1 million in sales.

Employment has risen from four workers in 2007 to 48 today, and Linda projects $7.3 million in sales this year.

Linda is not worried about advancement in online distance learning education hurting her business. If anything, she is expecting it to foster continued growth.

“To genuinely learn science concepts, you have to experience them,” she says.