Graph showing the relative absorbance of the urea-treated cortical (dark blue line) and nuclear (red line) membranes, and the alkali-treated cortical (green line) and nuclear (violet line) membranes between 380-500 nm. Binding buffer (light blue line) was used as negative control. To access the data, click or select the words “Appendix 2.” This will initiate the download of a compressed (pdf) archive that contains the file.