Plastic Lab Test Tube Rack
Here's a starting point for your "Dexter" Halloween party bar. Visit one of many online lab wholesalers and stock up on racks and plastic tubes. Fill with a deliciously grotesque looking potion (mini-Bloody Mary's? Blood Orange vodka and cranberry?) and line 'em up on a plastic sheet-swathed bar. Or to simulate various blood types, fill with different types of red wine.