A class in Puchi Puchi Virology
GamesRadar has posted a preview of the game that covers, in detail, this vital aspect of the game (the entire game). Basically, you tap three same-colored virii to create a triangle around them. Clicking any of the corners of this triangle causes it, and any virii inside the triangle, to disappear. If a virus stays onscreen too long, it turns to stone and can't be used to form a triangle.
It's nice to know that there's an interesting puzzle game to go along with the silly pop-culture references.