The last time I saw work incorporating an artist’s blood, he had AIDS and was using blood to make a statement. But aside from its clinical aspect, Nina Leo’s Trace 1 doesn’t suggest illness. For this installation she’s taken a sample of her blood each day since July 7, 2003, and placed it on a microscope slide, then dated it. Though the full version includes all the slides, only a portion of them are on the walls at Lobby; Trace 1a, also on display, consists of slides from the same series but stacked so they can’t be viewed individually. In the single row of mounted slides snaking across two walls, each blotch of blood creates a unique shape.

Best of Chicago voting is live now. Vote for your favorites »

Though Trace 1 is obsessive enough to hint at self-mutilation, it doesn’t communicate much emotion–and Leo says she prefers that viewers “take their own story from it.” Trace 2, the only other piece in the show, gives an idea of what she has in mind: to inject what she calls “forensic evidence” of herself and others into a space that’s typically filled with symbols. Eighteen locks of hair varying in color, texture, and length are mounted on a shelf and labeled with dates and times, while above them is a row of 16 Polaroids, usually showing a bedspread, a floor, or the ground, sometimes with human shadows. Leo says that each shot shows some sign of the person whose hair is mounted below it, whether it’s “an imprint on the covers or a mark on the gravel.” Three hair samples have no Polaroid (“I didn’t have my camera,” she says), and one Polaroid has no hair (“The person was bald”). Like the blood samples in Trace 1, the photos and locks of hair in Trace 2 don’t tell us much.

Where: Lobby, 731 N. Sangamon

Turrell is best known for his sublime light installations, in which he uses simple means to create areas of light that open up apparently infinite spaces. There are none in this exhibit, and in fact they’re rarely shown in Chicago. But two 2004 holograms, X-O and X-P, have some of their complexity. Though holograms usually create detailed three-dimensional views of recognizable objects, Turrell’s pieces are abstract, each showing a slab of blue hovering against black. The slabs, seen in depth head-on, move when the viewer does, stretching to one side or the other, which further dematerializes them. They gave me the same unsettled feeling Turrell’s installations do: if space and “objects” can be this insubstantial, how solid is my own body?