MAPT and red-green color blindness: Figure 1 shows the immunoblot of the total brain homgenates (TH) and the least soluble SDS-fraction. The majority of hyperphosphorylated tau was detected in the SDS fraction and was present in all PSP and CBD brain samples, although at different levels, thus confirming the pathology (Figure 1). Brain tissue was homogenized as weight per volume, and equal volumes of the subsequent individual fractions were separated by SDS-PAGE. Since α-tubulin was at approximately the same level in the TH of all brain samples, it was used to normalize data (Figure 1(b)).