Xylene, formamide, and acetic anhydride were purchased from Fisher Scientific (http://www.fishersci.com). Alizarin red S, toluidine blue, paraformaldehyde, polyvinylpyrrolidone, proteinase K, RNase A, tRNA, and dithiothreitol were purchased from Sigma (http://www.sigmaaldrich.com). Alcian blue 8GX was purchased from Electron Microscopy Science (http://www.emsdiasum.com). Dextran sulfate was purchased from Pharmacia (http://www.pharmacia.com).