The nucleotide contents and the estimated resolution based on FSC. (A) Analysis of the nucleotide contents by FPLC. Three chromatograms are shown: GDP-taxol microtubule (top), GMPCPP microtubule prepared by one cycle of GMPCPP uptake (middle), and GMPCPP microtubule prepared by three cycles of GMPCPP uptake (bottom). The occupancies of GMPCPP in the E site are shown at the right side of each chromatogram. mAU, milli-absorbance unit. (B) FSC function for the resolution estimation. The datasets of GMPCPP microtubule images were split in half to make two independent reconstructions, and the FSC function was calculated for the whole map (32.5 nm × 32.5 nm × 32.5 nm).