Fig. 1.

Localization of the folate transport systems at the brain barriers: A epithelial cells of the BCSFB, B microvessel endothelial cells of the BBB, C epithelial cells of the AB. Mouse brain sections were stained with the following: DAPI nuclear marker, AE390 anti-RFC (1:50) (Panel 1), anti-PCFT (1:50) (Panel 2), or anti-FRα (1:50) (Panel 3). The following cell markers were used to determine cell-specific localization: anti-Aqp-1 (1:100) (CP epithelial marker), anti-CD31 (1:50) (BBB endothelial marker), or anti-E-Cadherin (1:50) (AB epithelial marker). No primary antibody was used as a negative control (Panel 4). Arrows denote localization of RFC, PCFT, or FRα with cell markers. Sections were visualized using confocal microscopy (LSM 700; Carl Zeiss) operated with ZEN software using an oil-immersion 63× lens