Hi, We've just bought 1 gram of X-gal for 50 pounds from Alexis Corporation (based in San Diego, branches in Europe and Japan). This is considerably cheaper than other sources and also cheaper than Sigma's Bluo-Gal, which is 110.30 for 500mg. (usual disclaimer...I have no links to any of thee companies) Neil nsaunders at molbiol.ox.ac.uk