Lesley Ackerberg managed to scrape together $1,200 to buy an Art Nouveau screen when she was a college student at Berkeley in the mid-1970s. The antique store claimed it was made by the House of Guerlain in Paris. Now she wants to know if it's really valuable or a fake.

The Minnetonka resident will get her chance Saturday, when she and 6,000 others line up to have their prized possessions appraised on the popular PBS TV program "Antiques Roadshow" at the Minneapolis Convention Center.

What are the chances of Ackerberg and her antique screen making it on TV? Well, slim.

Only 90 of the thousands of items brought in will go before the TV cameras, and only a fraction of those will end up on the show that has aired in the United States since 1997, attracting 10 million viewers and a slew of imitators, including "Hollywood Treasures," "Pawn Stars" and "American Pickers."

But that doesn't seem to have curbed anyone's enthusiasm, said Bill Lowrie, a Twin Cities silver appraiser who volunteered to work for the show when it was taped in Minneapolis in 2005. "Everyone is having a good time despite the odds and the wait," he said.

Of the 35,000 people who applied for a free spot, only 3,000 were invited to Saturday's event. Each winner can bring a guest who also gets to bring one or two items.

After arriving at a specified time between 8 a.m. and 5 p.m., they'll wait in line to have their items appraised.

But even with reservations, wait times aren't short for those 6,000 fans. One man who stood in line for two hours with a 30-pound cast-iron clock "looked like he'd been branded" because of the indentations in his forearm, said Paul Hartquist, a watch appraiser in St. Paul who also appeared on the 2005 show.

Each person gets five to 10 minutes of face time with an appraiser, and the appraisals are free.

"It's a well-orchestrated event," said Tracy Luther, an auctioneer in North St. Paul who volunteered at the 2005 show.

When attendees enter the show space, they go to a "triage" table, where generalists such as Luther direct the hopeful person to a specialist in one of 22 categories, including military, silver, folk art, coins, posters and prints, glass, tribal arts, jewelry and musical instruments.

When appraisers spy an intriguing item or hear an interesting story, they pitch it to a producer for the show. If the item is deemed valuable, rare or steeped in history, they're whisked away to the "green room" while producers and appraisers debate its merits for appearing on air.

"The item might be rare and valuable, but that's no guarantee that it gets filmed," said show spokeswoman Judy Matthews. It helps if it has an interesting story, or is a good or bad example of restoration, or of local interest.

If an item gets a nod, its owner will go to makeup before taping. There is no dry run or coaching, and the estimated value is never revealed until cameras are rolling.

"Whenever the appraiser is giving the value, the person is always hearing it for the first time," Lowrie said. "It's the magic of spontaneity."

Some fans will get special treatment Saturday. Vince Marier of Chisago City, Minn., is bringing an elaborately carved table that might have spent time in the James J. Hill mansion in St. Paul and was later owned by the Hamm's beer family. He is one of 10 people selected by "Roadshow" producers to have their items picked up and returned on PBS' dime. Everyone else has to haul it themselves to the Convention Center or pay for a mover.

But size is no guarantee of high value. People with a $20 collectible instead of a rare antique are the norm, Luther said.

No one knows which items will be featured in Saturday's shows, which will air in 2012. But in 2005, the Twin Cities produced one of the most valuable finds ever shown on the program, a Patek Philippe watch that Hartquist valued at $250,000. It later sold at a Sotheby's auction in Geneva for $1.45 million.

Does any Minnesotan have a $1 million item sitting in a drawer waiting to be discovered? Stay tuned.