Figure 2From: Studies on the human choroid plexus in vitroSchematic representation of standard and inverted transwell filter systems. Most studies that explored vectorial processes across the CPE have used a standard transwell filter system. The inverted system was originally developed to analyze bacterial invasion and translocation in a porcine CPE in culture [23] and it enabled studies of bacterial interaction with the basolateral (blood) side of the CPE. Reproduced with permission from the author [22].Back to article page