The clock is ticking.

At 7 p.m. tonight the dancing will start – and until then, 500 dancers and 400 organizers are making their final preparations for Dance Marathon, the grueling 30-hour party and fund raiser that is the nation’s largest student-run philanthropy event.

With their fund raising finished, dancers are focusing on enjoying – and staying awake during – Northwestern’s biggest party of the quarter.

“I spent all afternoon with my partner raiding closets (for costumes),” said dancer Lily Rabe, a Speech freshman. “It’s definitely hitting us that we’re going to be dancing for 30 hours.”

Rabe said she had four major papers due this week, so she had to disregard the DM’s suggested ban on caffeine.

“I’m actually very, very short on sleep,” she said. “But I’m pretty good at running on zero. You find these reserves that you don’t think you have.”

For DM organizers busy turning Norris University Center into Bourbon Street – Mardi Gras is this year’s theme for decorations – the real work is just beginning. A minefield of electronic equipment and corporate banners littered the third floor of Norris on Thursday as DM committee members took care of “all the stuff you couldn’t do beforehand.”

That includes, according to Executive Co-Chairman Mark Waterston, a 2 a.m. journey into Chicago for fresh food.

“It’s just a matter of getting everything in place,” said Waterston, a Weinberg senior.

Organizers have planned a slew of non-dancing events to raise additional money, including a 5K walk, wine and beer tasting sessions, a silent auction, haircuts and several student performances.

But Waterston said he expected the highlight of the weekend to be the three-hour stretch on Saturday afternoon when several celebrities will make appearances and dancers will be rotated down to Norris’ ground floor to dance with visiting friends. “Survivor” host Jeff Probst, television stars Scott Wolf and Julie Benz and former Miss America, Kate Shindle, all will appear on Saturday.

Probst will host the final round of DM’s own “Survivor” game in the Louis Room on Saturday evening in what Waterston said will be another weekend highlight.

“I’m a ‘Survivor’ groupie,” he said.

In the Louis Room – the nerve center of DM weekend – organizers inflated balloons and made confetti Thursday as technicians worked on the light and sound systems.

Speech senior Jeffrey Porter, in his second year as DM lighting director, boasted that there will be 26 moving lights in Norris this weekend – more than in any other show on campus and three times as many as at the House of Blues in Chicago. According to Porter, the retail value of the lighting equipment for DM this year could top $500,000.

The chance to work with such equipment is the main draw for Porter, who will manage the system for all 30 hours of the marathon and said he has put in 50 hours of preparation this week.

For Saskia Van Gendt and Anne Mielke, DM’s appeal is slightly different. DM offers them the chance to raise money for a cause – the Elizabeth Glaser Pediatric AIDS Foundation, this year’s primary beneficiary – that they believe in.

“We were just inspired last year and wanted to be more involved,” said Van Gendt, a Weinberg sophomore.

The two dancers belong to Kappa Alpha Theta, for years DM’s top fund-raising sorority. Last year they canned for Theta, and this year they will dance as an independent couple.

They have applied the same fund-raising discipline to their own campaign, and the work has paid off: Van Gendt and Mielke raised $1,750 for DM, the highest total among independent couples. They also earned an audition to introduce Rosie O’Donnell on her television talk show.

With dancer fund raising largely completed by Feb. 21, Van Gendt and Mielke, an Education sophomore, have turned their efforts toward costumes and fitness. Van Gendt said they are making different sequined shirts for each of the 10 three-hour themed blocks of the marathon. They are especially excited about the ’80s block, she said.

“We’re so excited and a little bit nervous,” Van Gendt said. “We might be a little delirious in the middle, but we’re confident we’ll get through it.”

DM runs through 1 a.m. Sunday. The final hour, in which organizers will announce the grand fund-raising total and present checks to the Elizabeth Glaser Foundation and Evanston Community Foundation, is closed to the public.