An easy brain thick-section-clearing protocol to observe antigens in the brains of neurological disease mouse models by conventional epifluorescence and confocal laser scanning microscopy.

We developed a brain thick-section-clearing (BTS-C) procedure to observe coronal sections of the entire mouse brain with conventional epifluorescence microscopy (EFM). After clearing with the BTS procedure, the white light transmittance of the 1-mm-thick mouse brain sections was more than 96%. The distribution patterns of amyloid plaques or α-synuclein in 1-mm-thick brain sections of five different mouse strains cleared with this procedure were easily observed by EFM. In addition, the detailed distribution of antigens at higher magnifications was revealed by observing the same slides with a confocal laser scanning microscope (CLSM). In conclusion, we have shown that the BTS protocol can replace laborious and time-consuming semi-thin-sectioning procedures, and the cleared 1-mm-thick sections can be examined by EFM and CLSM to elucidate the distribution patterns of antigens.