VINCENZO NATALI is trim, bespectacled, bright, and, like almost all Canadians, polite - he doesn't seem at all like one of the sickest dudes in movies.

Yet his sci-fi horror movie "Splice," wherein human weakness meets DNA science, contains some truly sick stuff.

And not in the mindlessly repulsive manner of the modern "horror" movie - finding, say, a photo-realistic way of showing a drill bit going through some coed's frontal lobe.

Natali's aim is to make a true horror movie, with classic dimensions. It's why his meddling DNA scientists are named Clive and Elsa (Adrien Brody and Sarah Polley), lifted from actors who played in the prewar "Frankenstein" movies.

"Splice" is Frankenstein for a more graphic and sexually candid age, giving rise to scenes that give rise to controversy.

"It's a very divisive film. Some really embrace it, some think it's ridiculous, some are deeply offended, and frankly, I'm comfortable with all of those reactions," said Natali, who stopped in Philadelphia recently to promote the low-budget indie, not getting a big promotional push after being picked up by Warner Bros.

The new Clive and Elsa are corporate DNA scientists creating human-animal hybrids and harvesting the DNA for medical applications. They secretly create a nearly human female creature in order to get the human material they need.

They love her, she loves them, and, love being what it is, things get messy.

"It gets pretty Freudian really fast, in a big way. That's what made the film dangerous, and that's what made me want to make it," Natali said.

The creature, in movie terms, is also a hybrid - Natali started with actress (Delphine Chaneac), and gives her a digital makeover.

"It's a very intimate monster movie. We needed a real actor and the subtlety of a real performance. Other actors needed a real actor to play off of, because there's some really complex emotional stuff," Natali said.

"We altered the actor digitally. We replaced her legs, added a tail, altered facial features, removed a finger. My approach is less is more - that little changes to human anatomy would be more disturbing than a big one," said Natali, whose logic explains why Joan Rivers gets less terrifying over time.

Natali wanted viewers to feel, on a visceral level, what it means to see human DNA and animal DNA combined, and he needed tactile, real creatures to do that.

"I was determined to use real actors where possible. Also, I had to, because I didn't have any money."

For Natali, necessity is the mother of invention. For Clive and Elsa, it's curiosity, arrogance, hubris - ancient human failings that find new expression in "Splice."

"In some ways the film breaks new ground. It goes to places other films fear to tread, probably rightly and wisely. But the people who like this movie like it because the movie does not let them down. It suggests something is going to happen, then follows through. I think in mainstream cinema, they chicken out."